20929119561 has 45 divisors (see below), whose sum is σ = 35595477021. Its totient is φ = 11815406568.

The previous prime is 20929119553. The next prime is 20929119587. The reversal of 20929119561 is 16591192902.

The square root of 20929119561 is 144669.

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

It is not a de Polignac number, because 20929119561 - 2³ = 20929119553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20929119961) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 252158026 + ... + 252158108.

Almost surely, 2^20929119561 is an apocalyptic number.

20929119561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20929119561 is the 144669-th square number.

20929119561 is the 72335-th centered octagonal number.

It is an amenable number.

20929119561 is a deficient number, since it is larger than the sum of its proper divisors (14666357460).

20929119561 is an frugal number, since it uses more digits than its factorization.

20929119561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 45.

The spelling of 20929119561 in words is "twenty billion, nine hundred twenty-nine million, one hundred nineteen thousand, five hundred sixty-one".