20708125581 has 32 divisors (see below), whose sum is σ = 33484308480. Its totient is φ = 11211249600.

The previous prime is 20708125577. The next prime is 20708125591. The reversal of 20708125581 is 18552180702.

It is not a de Polignac number, because 20708125581 - 2² = 20708125577 is a prime.

It is a super-2 number, since 2×20708125581² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20708125531) 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, 765261 + ... + 791858.

It is an arithmetic number, because the mean of its divisors is an integer number (1046384640).

Almost surely, 2^20708125581 is an apocalyptic number.

It is an amenable number.

20708125581 is a deficient number, since it is larger than the sum of its proper divisors (12776182899).

20708125581 is a wasteful number, since it uses less digits than its factorization.

20708125581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557177.

The product of its (nonzero) digits is 44800, while the sum is 39.

The spelling of 20708125581 in words is "twenty billion, seven hundred eight million, one hundred twenty-five thousand, five hundred eighty-one".