20671767640 has 64 divisors (see below), whose sum is σ = 46871667360. Its totient is φ = 8204928000.

The previous prime is 20671767629. The next prime is 20671767671. The reversal of 20671767640 is 4676717602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2777364 + ... + 2784796.

Almost surely, 2^20671767640 is an apocalyptic number.

20671767640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20671767640 is an abundant number, since it is smaller than the sum of its proper divisors (26199899720).

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

20671767640 is a wasteful number, since it uses less digits than its factorization.

20671767640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7972 (or 7968 counting only the distinct ones).

The product of its (nonzero) digits is 592704, while the sum is 46.

The spelling of 20671767640 in words is "twenty billion, six hundred seventy-one million, seven hundred sixty-seven thousand, six hundred forty".