20397581061 has 32 divisors (see below), whose sum is σ = 32184770688. Its totient is φ = 11327907840.

The previous prime is 20397581051. The next prime is 20397581063. The reversal of 20397581061 is 16018579302.

It is not a de Polignac number, because 20397581061 - 2¹⁰ = 20397580037 is a prime.

It is a super-2 number, since 2×20397581061² (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 (20397581063) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 114756 + ... + 232301.

It is an arithmetic number, because the mean of its divisors is an integer number (1005774084).

Almost surely, 2^20397581061 is an apocalyptic number.

It is an amenable number.

20397581061 is a deficient number, since it is larger than the sum of its proper divisors (11787189627).

20397581061 is a wasteful number, since it uses less digits than its factorization.

20397581061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347221.

The product of its (nonzero) digits is 90720, while the sum is 42.

The spelling of 20397581061 in words is "twenty billion, three hundred ninety-seven million, five hundred eighty-one thousand, sixty-one".