72121210 has 32 divisors (see below), whose sum is σ = 149765760. Its totient is φ = 24493632.

The previous prime is 72121201. The next prime is 72121223. The reversal of 72121210 is 1212127.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2676 + ... + 12304.

It is an arithmetic number, because the mean of its divisors is an integer number (4680180).

Almost surely, 2^72121210 is an apocalyptic number.

72121210 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

72121210 is an abundant number, since it is smaller than the sum of its proper divisors (77644550).

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

72121210 is a wasteful number, since it uses less digits than its factorization.

72121210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9750.

The product of its (nonzero) digits is 56, while the sum is 16.

The square root of 72121210 is about 8492.4207385174. The cubic root of 72121210 is about 416.2500846191.

Adding to 72121210 its reverse (1212127), we get a palindrome (73333337).

The spelling of 72121210 in words is "seventy-two million, one hundred twenty-one thousand, two hundred ten".