150521681 has 4 divisors (see below), whose sum is σ = 150915072. Its totient is φ = 150128292.

The previous prime is 150521677. The next prime is 150521699. The reversal of 150521681 is 186125051.

150521681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 186125051 = 7 ⋅26589293.

It is a cyclic number.

It is not a de Polignac number, because 150521681 - 2² = 150521677 is a prime.

It is a super-2 number, since 2×150521681² = 45313552902131522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (150521641) 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, 196121 + ... + 196886.

It is an arithmetic number, because the mean of its divisors is an integer number (37728768).

Almost surely, 2^150521681 is an apocalyptic number.

It is an amenable number.

150521681 is a deficient number, since it is larger than the sum of its proper divisors (393391).

150521681 is an equidigital number, since it uses as much as digits as its factorization.

150521681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393390.

The product of its (nonzero) digits is 2400, while the sum is 29.

The square root of 150521681 is about 12268.7277661541. The cubic root of 150521681 is about 531.9445372014.

The spelling of 150521681 in words is "one hundred fifty million, five hundred twenty-one thousand, six hundred eighty-one".