21335629725 has 36 divisors (see below), whose sum is σ = 39875992416. Its totient is φ = 10884260640.

The previous prime is 21335629687. The next prime is 21335629801. The reversal of 21335629725 is 52792653312.

21335629725 is a `hidden beast` number, since 2 + 1 + 3 + 356 + 297 + 2 + 5 = 666.

It is not a de Polignac number, because 21335629725 - 2¹⁹ = 21335105437 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2056239 + ... + 2066588.

It is an arithmetic number, because the mean of its divisors is an integer number (1107666456).

Almost surely, 2^21335629725 is an apocalyptic number.

21335629725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21335629725 is a deficient number, since it is larger than the sum of its proper divisors (18540362691).

21335629725 is a wasteful number, since it uses less digits than its factorization.

21335629725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4122866 (or 4122858 counting only the distinct ones).

The product of its digits is 680400, while the sum is 45.

The spelling of 21335629725 in words is "twenty-one billion, three hundred thirty-five million, six hundred twenty-nine thousand, seven hundred twenty-five".