20515334400 has 864 divisors, whose sum is σ = 84309603840. Its totient is φ = 4838400000.

The previous prime is 20515334381. The next prime is 20515334401. The reversal of 20515334400 is 443351502.

20515334400 is a `hidden beast` number, since 205 + 1 + 53 + 3 + 4 + 400 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20515334401) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 81734275 + ... + 81734525.

It is an arithmetic number, because the mean of its divisors is an integer number (97580560).

Almost surely, 2^20515334400 is an apocalyptic number.

20515334400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20515334400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42154801920).

20515334400 is an abundant number, since it is smaller than the sum of its proper divisors (63794269440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20515334400 is a wasteful number, since it uses less digits than its factorization.

20515334400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 27.

Adding to 20515334400 its reverse (443351502), we get a palindrome (20958685902).

The spelling of 20515334400 in words is "twenty billion, five hundred fifteen million, three hundred thirty-four thousand, four hundred".