20965881615 has 96 divisors (see below), whose sum is σ = 40580844480. Its totient is φ = 9205088256.

The previous prime is 20965881593. The next prime is 20965881617. The reversal of 20965881615 is 51618856902.

It is a Cunningham number, because it is equal to 144796²-1.

It is not a de Polignac number, because 20965881615 - 2⁵ = 20965881583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20965881617) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4196559 + ... + 4201551.

It is an arithmetic number, because the mean of its divisors is an integer number (422717130).

Almost surely, 2^20965881615 is an apocalyptic number.

20965881615 is a deficient number, since it is larger than the sum of its proper divisors (19614962865).

20965881615 is a wasteful number, since it uses less digits than its factorization.

20965881615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5241 (or 5234 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 51.

The spelling of 20965881615 in words is "twenty billion, nine hundred sixty-five million, eight hundred eighty-one thousand, six hundred fifteen".