21350762161 has 9 divisors (see below), whose sum is σ = 22322930539. Its totient is φ = 20419253536.

The previous prime is 21350762149. The next prime is 21350762171. The reversal of 21350762161 is 16126705312.

The square root of 21350762161 is 146119.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 9803970225 + 11546791936 = 99015^2 + 107456^2 .

It is not a de Polignac number, because 21350762161 - 2¹⁷ = 21350631089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21350762171) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3357561 + ... + 3363913.

Almost surely, 2^21350762161 is an apocalyptic number.

21350762161 is the 146119-th square number.

21350762161 is the 73060-th centered octagonal number.

It is an amenable number.

21350762161 is a deficient number, since it is larger than the sum of its proper divisors (972168378).

21350762161 is an frugal number, since it uses more digits than its factorization.

21350762161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12752 (or 6376 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 21350762161 in words is "twenty-one billion, three hundred fifty million, seven hundred sixty-two thousand, one hundred sixty-one".