151605621 has 8 divisors (see below), whose sum is σ = 224600960. Its totient is φ = 101070396.

The previous prime is 151605589. The next prime is 151605631. The reversal of 151605621 is 126506151.

It is a happy number.

151605621 is a `hidden beast` number, since 1 + 51 + 605 + 6 + 2 + 1 = 666.

It is not a de Polignac number, because 151605621 - 2⁵ = 151605589 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 5615023 = 151605621 / (1 + 5 + 1 + 6 + 0 + 5 + 6 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (151605631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2807485 + ... + 2807538.

It is an arithmetic number, because the mean of its divisors is an integer number (28075120).

Almost surely, 2^151605621 is an apocalyptic number.

It is an amenable number.

151605621 is a deficient number, since it is larger than the sum of its proper divisors (72995339).

151605621 is an equidigital number, since it uses as much as digits as its factorization.

151605621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5615032 (or 5615026 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 151605621 is about 12312.8234373762. The cubic root of 151605621 is about 533.2183678847.

The spelling of 151605621 in words is "one hundred fifty-one million, six hundred five thousand, six hundred twenty-one".