20952547581 has 16 divisors (see below), whose sum is σ = 31931015168. Its totient is φ = 11971638000.

The previous prime is 20952547573. The next prime is 20952547591. The reversal of 20952547581 is 18574525902.

It is not a de Polignac number, because 20952547581 - 2³ = 20952547573 is a prime.

It is a super-2 number, since 2×20952547581² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20952547581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20952547571) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 178356 + ... + 271506.

It is an arithmetic number, because the mean of its divisors is an integer number (1995688448).

Almost surely, 2^20952547581 is an apocalyptic number.

20952547581 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20952547581 is a deficient number, since it is larger than the sum of its proper divisors (10978467587).

20952547581 is a wasteful number, since it uses less digits than its factorization.

20952547581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103872.

The product of its (nonzero) digits is 1008000, while the sum is 48.

The spelling of 20952547581 in words is "twenty billion, nine hundred fifty-two million, five hundred forty-seven thousand, five hundred eighty-one".