72639402 has 64 divisors (see below), whose sum is σ = 169734528. Its totient is φ = 20480000.

The previous prime is 72639379. The next prime is 72639407. The reversal of 72639402 is 20493627.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (72639407) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 113002 + ... + 113642.

It is an arithmetic number, because the mean of its divisors is an integer number (2652102).

Almost surely, 2^72639402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72639402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84867264).

72639402 is an abundant number, since it is smaller than the sum of its proper divisors (97095126).

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

72639402 is a wasteful number, since it uses less digits than its factorization.

72639402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 775.

The product of its (nonzero) digits is 18144, while the sum is 33.

The square root of 72639402 is about 8522.8752190795. The cubic root of 72639402 is about 417.2446275540.

The spelling of 72639402 in words is "seventy-two million, six hundred thirty-nine thousand, four hundred two".