21204663510 has 32 divisors (see below), whose sum is σ = 50899932000. Its totient is φ = 5653605888.

The previous prime is 21204663509. The next prime is 21204663517. The reversal of 21204663510 is 1536640212.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204663517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126366 + ... + 241614.

It is an arithmetic number, because the mean of its divisors is an integer number (1590622875).

Almost surely, 2^21204663510 is an apocalyptic number.

21204663510 is an abundant number, since it is smaller than the sum of its proper divisors (29695268490).

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

21204663510 is a wasteful number, since it uses less digits than its factorization.

21204663510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121392.

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 21204663510 in words is "twenty-one billion, two hundred four million, six hundred sixty-three thousand, five hundred ten".