72721012 has 24 divisors (see below), whose sum is σ = 156630656. Its totient is φ = 28768608.

The previous prime is 72721007. The next prime is 72721013. The reversal of 72721012 is 21012727.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72721013) 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, 99528 + ... + 100255.

Almost surely, 2^72721012 is an apocalyptic number.

It is an amenable number.

72721012 is an abundant number, since it is smaller than the sum of its proper divisors (83909644).

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

72721012 is a wasteful number, since it uses less digits than its factorization.

72721012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199807 (or 199805 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 72721012 is about 8527.6615786510. The cubic root of 72721012 is about 417.4008264805.

Adding to 72721012 its reverse (21012727), we get a palindrome (93733739).

The spelling of 72721012 in words is "seventy-two million, seven hundred twenty-one thousand, twelve".