156720061 has 4 divisors (see below), whose sum is σ = 156753724. Its totient is φ = 156686400.

The previous prime is 156720007. The next prime is 156720071. The reversal of 156720061 is 160027651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 160027651 = 7 ⋅22861093.

It can be written as a sum of positive squares in 2 ways, for example, as 43956900 + 112763161 = 6630^2 + 10619^2 .

It is a cyclic number.

It is not a de Polignac number, because 156720061 - 2²³ = 148331453 is a prime.

It is a super-2 number, since 2×156720061² = 49122355039687442, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (156720071) 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, 8460 + ... + 19621.

It is an arithmetic number, because the mean of its divisors is an integer number (39188431).

Almost surely, 2^156720061 is an apocalyptic number.

It is an amenable number.

156720061 is a deficient number, since it is larger than the sum of its proper divisors (33663).

156720061 is an equidigital number, since it uses as much as digits as its factorization.

156720061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33662.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 156720061 is about 12518.7883199613. The cubic root of 156720061 is about 539.1482468390.

The spelling of 156720061 in words is "one hundred fifty-six million, seven hundred twenty thousand, sixty-one".