72021558 has 48 divisors (see below), whose sum is σ = 170576640. Its totient is φ = 19858272.

The previous prime is 72021557. The next prime is 72021563. The reversal of 72021558 is 85512027.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72021557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34303 + ... + 36341.

It is an arithmetic number, because the mean of its divisors is an integer number (3553680).

Almost surely, 2^72021558 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72021558, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85288320).

72021558 is an abundant number, since it is smaller than the sum of its proper divisors (98555082).

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

72021558 is a wasteful number, since it uses less digits than its factorization.

72021558 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2109 (or 2080 counting only the distinct ones).

The product of its (nonzero) digits is 5600, while the sum is 30.

The square root of 72021558 is about 8486.5515964967. The cubic root of 72021558 is about 416.0582812514.

The spelling of 72021558 in words is "seventy-two million, twenty-one thousand, five hundred fifty-eight".