72121506 has 16 divisors (see below), whose sum is σ = 145864800. Its totient is φ = 23770208.

The previous prime is 72121493. The next prime is 72121507. The reversal of 72121506 is 60512127.

It is not an unprimeable number, because it can be changed into a prime (72121507) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66996 + ... + 68063.

It is an arithmetic number, because the mean of its divisors is an integer number (9116550).

Almost surely, 2^72121506 is an apocalyptic number.

72121506 is an abundant number, since it is smaller than the sum of its proper divisors (73743294).

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

72121506 is a wasteful number, since it uses less digits than its factorization.

72121506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135153.

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 72121506 is about 8492.4381658037. The cubic root of 72121506 is about 416.2506540765.

It can be divided in two parts, 72121 and 506, that added together give a palindrome (72627).

The spelling of 72121506 in words is "seventy-two million, one hundred twenty-one thousand, five hundred six".