21052507652 has 12 divisors (see below), whose sum is σ = 40191151056. Its totient is φ = 9569321640.

The previous prime is 21052507649. The next prime is 21052507669. The reversal of 21052507652 is 25670525012.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239232998 + ... + 239233085.

It is an arithmetic number, because the mean of its divisors is an integer number (3349262588).

Almost surely, 2^21052507652 is an apocalyptic number.

21052507652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21052507652 is a deficient number, since it is larger than the sum of its proper divisors (19138643404).

21052507652 is a wasteful number, since it uses less digits than its factorization.

21052507652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478466098 (or 478466096 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 35.

The spelling of 21052507652 in words is "twenty-one billion, fifty-two million, five hundred seven thousand, six hundred fifty-two".