20100787640 has 16 divisors (see below), whose sum is σ = 45226772280. Its totient is φ = 8040315040.

The previous prime is 20100787639. The next prime is 20100787643. The reversal of 20100787640 is 4678700102.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20100787640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100787643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 251259806 + ... + 251259885.

Almost surely, 2^20100787640 is an apocalyptic number.

20100787640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20100787640 is an abundant number, since it is smaller than the sum of its proper divisors (25125984640).

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

20100787640 is a wasteful number, since it uses less digits than its factorization.

20100787640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502519702 (or 502519698 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 35.

The spelling of 20100787640 in words is "twenty billion, one hundred million, seven hundred eighty-seven thousand, six hundred forty".