71920638 has 36 divisors (see below), whose sum is σ = 161420688. Its totient is φ = 23142000.

The previous prime is 71920627. The next prime is 71920697. The reversal of 71920638 is 83602917.

71920638 is a `hidden beast` number, since 7 + 19 + 2 + 0 + 638 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12763 + ... + 17513.

It is an arithmetic number, because the mean of its divisors is an integer number (4483908).

Almost surely, 2^71920638 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71920638, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80710344).

71920638 is an abundant number, since it is smaller than the sum of its proper divisors (89500050).

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

71920638 is a wasteful number, since it uses less digits than its factorization.

71920638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4817 (or 4785 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 71920638 is about 8480.6036341760. The cubic root of 71920638 is about 415.8638569228.

The spelling of 71920638 in words is "seventy-one million, nine hundred twenty thousand, six hundred thirty-eight".