20356416261 has 20 divisors (see below), whose sum is σ = 30417508044. Its totient is φ = 13567132800.

The previous prime is 20356416253. The next prime is 20356416263. The reversal of 20356416261 is 16261465302.

20356416261 is a `hidden beast` number, since 2 + 0 + 3 + 5 + 641 + 6 + 2 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5659703361 + 14696712900 = 75231^2 + 121230^2 .

It is not a de Polignac number, because 20356416261 - 2³ = 20356416253 is a prime.

It is a super-2 number, since 2×20356416261² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20356416263) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 271231 + ... + 338051.

Almost surely, 2^20356416261 is an apocalyptic number.

It is an amenable number.

20356416261 is a deficient number, since it is larger than the sum of its proper divisors (10061091783).

20356416261 is an equidigital number, since it uses as much as digits as its factorization.

20356416261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70594 (or 70585 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 20356416261 in words is "twenty billion, three hundred fifty-six million, four hundred sixteen thousand, two hundred sixty-one".