72120405 has 24 divisors (see below), whose sum is σ = 134233632. Its totient is φ = 32968992.

The previous prime is 72120383. The next prime is 72120407. The reversal of 72120405 is 50402127.

It is not a de Polignac number, because 72120405 - 2¹⁰ = 72119381 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72120407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 48327 + ... + 49796.

It is an arithmetic number, because the mean of its divisors is an integer number (5593068).

Almost surely, 2^72120405 is an apocalyptic number.

It is an amenable number.

72120405 is a deficient number, since it is larger than the sum of its proper divisors (62113227).

72120405 is a wasteful number, since it uses less digits than its factorization.

72120405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98145 (or 98138 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 72120405 is about 8492.3733431827. The cubic root of 72120405 is about 416.2485359182.

The spelling of 72120405 in words is "seventy-two million, one hundred twenty thousand, four hundred five".