20149535640 has 64 divisors (see below), whose sum is σ = 65098504800. Its totient is φ = 4959885312.

The previous prime is 20149535621. The next prime is 20149535699. The reversal of 20149535640 is 4653594102.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6456625 + ... + 6459744.

Almost surely, 2^20149535640 is an apocalyptic number.

20149535640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20149535640 is an abundant number, since it is smaller than the sum of its proper divisors (44948969160).

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

20149535640 is a wasteful number, since it uses less digits than its factorization.

20149535640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12916396 (or 12916392 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 39.

The spelling of 20149535640 in words is "twenty billion, one hundred forty-nine million, five hundred thirty-five thousand, six hundred forty".