21260551138 has 8 divisors (see below), whose sum is σ = 31908658140. Its totient is φ = 10624331760.

The previous prime is 21260551129. The next prime is 21260551181. The reversal of 21260551138 is 83115506212.

It can be written as a sum of positive squares in 2 ways, for example, as 21258514809 + 2036329 = 145803^2 + 1427^2 .

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

It is a super-2 number, since 2×21260551138² (a number of 21 digits) contains 22 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, 2967433 + ... + 2974588.

Almost surely, 2^21260551138 is an apocalyptic number.

21260551138 is a deficient number, since it is larger than the sum of its proper divisors (10648107002).

21260551138 is a wasteful number, since it uses less digits than its factorization.

21260551138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5943812.

The product of its (nonzero) digits is 14400, while the sum is 34.

The spelling of 21260551138 in words is "twenty-one billion, two hundred sixty million, five hundred fifty-one thousand, one hundred thirty-eight".