72155515 has 4 divisors (see below), whose sum is σ = 86586624. Its totient is φ = 57724408.

The previous prime is 72155491. The next prime is 72155537. The reversal of 72155515 is 51555127.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 72155515 - 2¹¹ = 72153467 is a prime.

It is a Duffinian number.

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, 7215547 + ... + 7215556.

It is an arithmetic number, because the mean of its divisors is an integer number (21646656).

Almost surely, 2^72155515 is an apocalyptic number.

72155515 is a deficient number, since it is larger than the sum of its proper divisors (14431109).

72155515 is a wasteful number, since it uses less digits than its factorization.

72155515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14431108.

The product of its digits is 8750, while the sum is 31.

The square root of 72155515 is about 8494.4402405338. The cubic root of 72155515 is about 416.3160716601.

The spelling of 72155515 in words is "seventy-two million, one hundred fifty-five thousand, five hundred fifteen".