20661244505 has 32 divisors (see below), whose sum is σ = 27305220096. Its totient is φ = 14883840000.

The previous prime is 20661244469. The next prime is 20661244519. The reversal of 20661244505 is 50544216602.

It is not a de Polignac number, because 20661244505 - 2⁸ = 20661244249 is a prime.

It is a super-3 number, since 3×20661244505³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2527625 + ... + 2535785.

It is an arithmetic number, because the mean of its divisors is an integer number (853288128).

Almost surely, 2^20661244505 is an apocalyptic number.

It is an amenable number.

20661244505 is a deficient number, since it is larger than the sum of its proper divisors (6643975591).

20661244505 is a wasteful number, since it uses less digits than its factorization.

20661244505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8609.

The product of its (nonzero) digits is 57600, while the sum is 35.

The spelling of 20661244505 in words is "twenty billion, six hundred sixty-one million, two hundred forty-four thousand, five hundred five".