21019704552 has 256 divisors, whose sum is σ = 72953395200. Its totient is φ = 5447831040.

The previous prime is 21019704533. The next prime is 21019704611. The reversal of 21019704552 is 25540791012.

21019704552 is a `hidden beast` number, since 2 + 10 + 1 + 97 + 0 + 4 + 552 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 9761908 + ... + 9764060.

It is an arithmetic number, because the mean of its divisors is an integer number (284974200).

Almost surely, 2^21019704552 is an apocalyptic number.

21019704552 is a gapful number since it is divisible by the number (22) 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 21019704552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36476697600).

21019704552 is an abundant number, since it is smaller than the sum of its proper divisors (51933690648).

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

21019704552 is a wasteful number, since it uses less digits than its factorization.

21019704552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2773 (or 2763 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The spelling of 21019704552 in words is "twenty-one billion, nineteen million, seven hundred four thousand, five hundred fifty-two".