70720031 has 2 divisors, whose sum is σ = 70720032. Its totient is φ = 70720030.

The previous prime is 70719977. The next prime is 70720043. The reversal of 70720031 is 13002707.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-70720031 is a prime.

It is a super-2 number, since 2×70720031² = 10002645569281922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 70719985 and 70720012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70720231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35360015 + 35360016.

It is an arithmetic number, because the mean of its divisors is an integer number (35360016).

Almost surely, 2^70720031 is an apocalyptic number.

70720031 is a deficient number, since it is larger than the sum of its proper divisors (1).

70720031 is an equidigital number, since it uses as much as digits as its factorization.

70720031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 294, while the sum is 20.

The square root of 70720031 is about 8409.5202598008. The cubic root of 70720031 is about 413.5367853902.

Adding to 70720031 its reverse (13002707), we get a palindrome (83722738).

The spelling of 70720031 in words is "seventy million, seven hundred twenty thousand, thirty-one".