161325621 has 8 divisors (see below), whose sum is σ = 239000960. Its totient is φ = 107550396.

The previous prime is 161325613. The next prime is 161325623. The reversal of 161325621 is 126523161.

161325621 is a `hidden beast` number, since 1 + 6 + 1 + 32 + 5 + 621 = 666.

161325621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 161325621 - 2³ = 161325613 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: 5975023 = 161325621 / (1 + 6 + 1 + 3 + 2 + 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 (161325623) 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, 2987485 + ... + 2987538.

It is an arithmetic number, because the mean of its divisors is an integer number (29875120).

Almost surely, 2^161325621 is an apocalyptic number.

It is an amenable number.

161325621 is a deficient number, since it is larger than the sum of its proper divisors (77675339).

161325621 is an equidigital number, since it uses as much as digits as its factorization.

161325621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5975032 (or 5975026 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 161325621 is about 12701.4023241530. The cubic root of 161325621 is about 544.3786887575.

Adding to 161325621 its reverse (126523161), we get a palindrome (287848782).

The spelling of 161325621 in words is "one hundred sixty-one million, three hundred twenty-five thousand, six hundred twenty-one".