21553305938 has 8 divisors (see below), whose sum is σ = 32336891388. Its totient is φ = 10774342144.

The previous prime is 21553305913. The next prime is 21553305941. The reversal of 21553305938 is 83950335512.

It can be written as a sum of positive squares in 2 ways, for example, as 16683080569 + 4870225369 = 129163^2 + 69787^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×21553305938³ (a number of 32 digits) contains 333 as substring.

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, 1143731 + ... + 1162422.

Almost surely, 2^21553305938 is an apocalyptic number.

21553305938 is a deficient number, since it is larger than the sum of its proper divisors (10783585450).

21553305938 is a wasteful number, since it uses less digits than its factorization.

21553305938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2310828.

The product of its (nonzero) digits is 486000, while the sum is 44.

The spelling of 21553305938 in words is "twenty-one billion, five hundred fifty-three million, three hundred five thousand, nine hundred thirty-eight".