1625660161 has 4 divisors (see below), whose sum is σ = 1645246512. Its totient is φ = 1606073812.

The previous prime is 1625660147. The next prime is 1625660167. The reversal of 1625660161 is 1610665261.

It is a happy number.

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: 1610665261 = 4357 ⋅369673.

It is a cyclic number.

It is not a de Polignac number, because 1625660161 - 2⁵ = 1625660129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1625660167) 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, 9793051 + ... + 9793216.

It is an arithmetic number, because the mean of its divisors is an integer number (411311628).

Almost surely, 2^1625660161 is an apocalyptic number.

It is an amenable number.

1625660161 is a deficient number, since it is larger than the sum of its proper divisors (19586351).

1625660161 is an equidigital number, since it uses as much as digits as its factorization.

1625660161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19586350.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 1625660161 is about 40319.4761994746. The cubic root of 1625660161 is about 1175.8265284043.

The spelling of 1625660161 in words is "one billion, six hundred twenty-five million, six hundred sixty thousand, one hundred sixty-one".