72121772 has 12 divisors (see below), whose sum is σ = 126680736. Its totient is φ = 35927280.

The previous prime is 72121757. The next prime is 72121787. The reversal of 72121772 is 27712127.

It is an interprime number because it is at equal distance from previous prime (72121757) and next prime (72121787).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32183 + ... + 34350.

It is an arithmetic number, because the mean of its divisors is an integer number (10556728).

Almost surely, 2^72121772 is an apocalyptic number.

It is an amenable number.

72121772 is a deficient number, since it is larger than the sum of its proper divisors (54558964).

72121772 is a wasteful number, since it uses less digits than its factorization.

72121772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66808 (or 66806 counting only the distinct ones).

The product of its digits is 2744, while the sum is 29.

The square root of 72121772 is about 8492.4538267806. The cubic root of 72121772 is about 416.2511658172.

Adding to 72121772 its reverse (27712127), we get a palindrome (99833899).

The spelling of 72121772 in words is "seventy-two million, one hundred twenty-one thousand, seven hundred seventy-two".