20151815040 has 768 divisors, whose sum is σ = 83725125120. Its totient is φ = 4536705024.

The previous prime is 20151815029. The next prime is 20151815119. The reversal of 20151815040 is 4051815102.

20151815040 is a `hidden beast` number, since 2 + 0 + 151 + 8 + 1 + 504 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 20151814995 and 20151815013.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 116484394 + ... + 116484566.

It is an arithmetic number, because the mean of its divisors is an integer number (109017090).

Almost surely, 2^20151815040 is an apocalyptic number.

20151815040 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 20151815040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41862562560).

20151815040 is an abundant number, since it is smaller than the sum of its proper divisors (63573310080).

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

20151815040 is a wasteful number, since it uses less digits than its factorization.

20151815040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 297 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The spelling of 20151815040 in words is "twenty billion, one hundred fifty-one million, eight hundred fifteen thousand, forty".