20661537630 has 16 divisors (see below), whose sum is σ = 49587690384. Its totient is φ = 5509743360.

The previous prime is 20661537529. The next prime is 20661537667. The reversal of 20661537630 is 3673516602.

It is a congruent number.

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, 344358931 + ... + 344358990.

It is an arithmetic number, because the mean of its divisors is an integer number (3099230649).

Almost surely, 2^20661537630 is an apocalyptic number.

20661537630 is an abundant number, since it is smaller than the sum of its proper divisors (28926152754).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20661537630 is a wasteful number, since it uses less digits than its factorization.

20661537630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688717931.

The product of its (nonzero) digits is 136080, while the sum is 39.

The spelling of 20661537630 in words is "twenty billion, six hundred sixty-one million, five hundred thirty-seven thousand, six hundred thirty".