21339902690 has 8 divisors (see below), whose sum is σ = 38411824860. Its totient is φ = 8535961072.

The previous prime is 21339902657. The next prime is 21339902707. The reversal of 21339902690 is 9620993312.

It can be written as a sum of positive squares in 2 ways, for example, as 17228400049 + 4111502641 = 131257^2 + 64121^2 .

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

It is a super-2 number, since 2×21339902690² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

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, 1066995125 + ... + 1066995144.

Almost surely, 2^21339902690 is an apocalyptic number.

21339902690 is a deficient number, since it is larger than the sum of its proper divisors (17071922170).

21339902690 is a wasteful number, since it uses less digits than its factorization.

21339902690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133990276.

The product of its (nonzero) digits is 157464, while the sum is 44.

The spelling of 21339902690 in words is "twenty-one billion, three hundred thirty-nine million, nine hundred two thousand, six hundred ninety".