21057677450 has 24 divisors (see below), whose sum is σ = 39185807052. Its totient is φ = 8419086720.

The previous prime is 21057677437. The next prime is 21057677471. The reversal of 21057677450 is 5477675012.

It can be written as a sum of positive squares in 6 ways, for example, as 6744187129 + 14313490321 = 82123^2 + 119639^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8312 + ... + 205388.

Almost surely, 2^21057677450 is an apocalyptic number.

21057677450 is a deficient number, since it is larger than the sum of its proper divisors (18128129602).

21057677450 is a wasteful number, since it uses less digits than its factorization.

21057677450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199226 (or 199221 counting only the distinct ones).

The product of its (nonzero) digits is 411600, while the sum is 44.

The spelling of 21057677450 in words is "twenty-one billion, fifty-seven million, six hundred seventy-seven thousand, four hundred fifty".