21040647804 has 144 divisors (see below), whose sum is σ = 63337572480. Its totient is φ = 6040319040.

The previous prime is 21040647781. The next prime is 21040647811. The reversal of 21040647804 is 40874604012.

21040647804 is a `hidden beast` number, since 2 + 1 + 0 + 4 + 0 + 647 + 8 + 0 + 4 = 666.

It is a hoax number, since the sum of its digits (36) 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 (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 151362 + ... + 254934.

Almost surely, 2^21040647804 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21040647804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31668786240).

21040647804 is an abundant number, since it is smaller than the sum of its proper divisors (42296924676).

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

21040647804 is a wasteful number, since it uses less digits than its factorization.

21040647804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103622 (or 103608 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 21040647804 in words is "twenty-one billion, forty million, six hundred forty-seven thousand, eight hundred four".