151560721 has 9 divisors (see below), whose sum is σ = 164289531. Its totient is φ = 139754472.

The previous prime is 151560713. The next prime is 151560733. The reversal of 151560721 is 127065151.

The square root of 151560721 is 12311.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 22420225 + 129140496 = 4735^2 + 11364^2 .

It is not a de Polignac number, because 151560721 - 2³ = 151560713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 151560721.

It is not an unprimeable number, because it can be changed into a prime (151560751) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 159570 + ... + 160516.

Almost surely, 2^151560721 is an apocalyptic number.

151560721 is the 12311-st square number.

151560721 is the 6156-th centered octagonal number.

It is an amenable number.

151560721 is a deficient number, since it is larger than the sum of its proper divisors (12728810).

151560721 is an frugal number, since it uses more digits than its factorization.

151560721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1920 (or 960 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 28.

The cubic root of 151560721 is about 533.1657228080.

The spelling of 151560721 in words is "one hundred fifty-one million, five hundred sixty thousand, seven hundred twenty-one".