70721331 has 4 divisors (see below), whose sum is σ = 94295112. Its totient is φ = 47147552.

The previous prime is 70721317. The next prime is 70721341. The reversal of 70721331 is 13312707.

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 70721331 - 2¹¹ = 70719283 is a prime.

It is a super-2 number, since 2×70721331² = 10003013316823122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (70721341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11786886 + ... + 11786891.

It is an arithmetic number, because the mean of its divisors is an integer number (23573778).

Almost surely, 2^70721331 is an apocalyptic number.

70721331 is a deficient number, since it is larger than the sum of its proper divisors (23573781).

70721331 is a wasteful number, since it uses less digits than its factorization.

70721331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23573780.

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 70721331 is about 8409.5975527964. The cubic root of 70721331 is about 413.5393192999.

The spelling of 70721331 in words is "seventy million, seven hundred twenty-one thousand, three hundred thirty-one".