20661610690 has 16 divisors (see below), whose sum is σ = 42503884992. Its totient is φ = 7083980784.

The previous prime is 20661610679. The next prime is 20661610721. The reversal of 20661610690 is 9601616602.

It is a super-2 number, since 2×20661610690² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 147582864 + ... + 147583003.

It is an arithmetic number, because the mean of its divisors is an integer number (2656492812).

Almost surely, 2^20661610690 is an apocalyptic number.

20661610690 is an abundant number, since it is smaller than the sum of its proper divisors (21842274302).

20661610690 is a wasteful number, since it uses less digits than its factorization.

20661610690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295165881.

The product of its (nonzero) digits is 23328, while the sum is 37.

The spelling of 20661610690 in words is "twenty billion, six hundred sixty-one million, six hundred ten thousand, six hundred ninety".