20233991640 has 32 divisors (see below), whose sum is σ = 60701975280. Its totient is φ = 5395731072.

The previous prime is 20233991623. The next prime is 20233991653. The reversal of 20233991640 is 4619933202.

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, 84308179 + ... + 84308418.

Almost surely, 2^20233991640 is an apocalyptic number.

20233991640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20233991640 is an abundant number, since it is smaller than the sum of its proper divisors (40467983640).

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

20233991640 is a wasteful number, since it uses less digits than its factorization.

20233991640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168616611 (or 168616607 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 39.

The spelling of 20233991640 in words is "twenty billion, two hundred thirty-three million, nine hundred ninety-one thousand, six hundred forty".