21307565918290 has 16 divisors (see below), whose sum is σ = 38401741149912. Its totient is φ = 8512332479104.

The previous prime is 21307565918251. The next prime is 21307565918297. The reversal of 21307565918290 is 9281956570312.

It can be written as a sum of positive squares in 4 ways, for example, as 11882008926841 + 9425556991449 = 3447029^2 + 3070107^2 .

It is not an unprimeable number, because it can be changed into a prime (21307565918297) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1336727659 + ... + 1336743598.

Almost surely, 2^{21307565918290} is an apocalyptic number.

21307565918290 is a deficient number, since it is larger than the sum of its proper divisors (17094175231622).

21307565918290 is a wasteful number, since it uses less digits than its factorization.

21307565918290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2673472061.

The product of its (nonzero) digits is 8164800, while the sum is 58.

The spelling of 21307565918290 in words is "twenty-one trillion, three hundred seven billion, five hundred sixty-five million, nine hundred eighteen thousand, two hundred ninety".