20940619661 has 16 divisors (see below), whose sum is σ = 23325818880. Its totient is φ = 18675204480.

The previous prime is 20940619639. The next prime is 20940619697. The reversal of 20940619661 is 16691604902.

It is a cyclic number.

It is not a de Polignac number, because 20940619661 - 2²² = 20936425357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20940619061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 135821 + ... + 245618.

It is an arithmetic number, because the mean of its divisors is an integer number (1457863680).

Almost surely, 2^20940619661 is an apocalyptic number.

It is an amenable number.

20940619661 is a deficient number, since it is larger than the sum of its proper divisors (2385199219).

20940619661 is a wasteful number, since it uses less digits than its factorization.

20940619661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 381596.

The product of its (nonzero) digits is 139968, while the sum is 44.

The spelling of 20940619661 in words is "twenty billion, nine hundred forty million, six hundred nineteen thousand, six hundred sixty-one".