21057403657770 has 24 divisors (see below), whose sum is σ = 54749249510436. Its totient is φ = 5615307642048.

The previous prime is 21057403657751. The next prime is 21057403657859. The reversal of 21057403657770 is 7775630475012.

21057403657770 is a `hidden beast` number, since 2 + 1 + 0 + 574 + 0 + 3 + 65 + 7 + 7 + 7 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 20842685413641 + 214718244129 = 4565379^2 + 463377^2 .

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, 116985575787 + ... + 116985575966.

Almost surely, 2^{21057403657770} is an apocalyptic number.

21057403657770 is an abundant number, since it is smaller than the sum of its proper divisors (33691845852666).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21057403657770 is a wasteful number, since it uses less digits than its factorization.

21057403657770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233971151766 (or 233971151763 counting only the distinct ones).

The product of its (nonzero) digits is 8643600, while the sum is 54.

The spelling of 21057403657770 in words is "twenty-one trillion, fifty-seven billion, four hundred three million, six hundred fifty-seven thousand, seven hundred seventy".