72157890 has 96 divisors (see below), whose sum is σ = 203295744. Its totient is φ = 16343040.

The previous prime is 72157873. The next prime is 72157901. The reversal of 72157890 is 9875127.

It is a super-2 number, since 2×72157890² = 10413522178504200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 280642 + ... + 280898.

It is an arithmetic number, because the mean of its divisors is an integer number (2117664).

Almost surely, 2^72157890 is an apocalyptic number.

72157890 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 72157890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101647872).

72157890 is an abundant number, since it is smaller than the sum of its proper divisors (131137854).

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

72157890 is a wasteful number, since it uses less digits than its factorization.

72157890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 72157890 is about 8494.5800367058. The cubic root of 72157890 is about 416.3206392935.

The spelling of 72157890 in words is "seventy-two million, one hundred fifty-seven thousand, eight hundred ninety".