151567721 has 4 divisors (see below), whose sum is σ = 151813200. Its totient is φ = 151322244.

The previous prime is 151567709. The next prime is 151567727. The reversal of 151567721 is 127765151.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127765151 = 971 ⋅131581.

It is a cyclic number.

It is not a de Polignac number, because 151567721 - 2¹⁸ = 151305577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (151567727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121811 + ... + 123048.

It is an arithmetic number, because the mean of its divisors is an integer number (37953300).

Almost surely, 2^151567721 is an apocalyptic number.

It is an amenable number.

151567721 is a deficient number, since it is larger than the sum of its proper divisors (245479).

151567721 is an equidigital number, since it uses as much as digits as its factorization.

151567721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245478.

The product of its digits is 14700, while the sum is 35.

The square root of 151567721 is about 12311.2842953122. The cubic root of 151567721 is about 533.1739309651.

The spelling of 151567721 in words is "one hundred fifty-one million, five hundred sixty-seven thousand, seven hundred twenty-one".