161251651 has 16 divisors (see below), whose sum is σ = 187027200. Its totient is φ = 137484000.

The previous prime is 161251639. The next prime is 161251663. The reversal of 161251651 is 156152161.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (161251639) and next prime (161251663).

It is not a de Polignac number, because 161251651 - 2⁵ = 161251619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161251621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17290 + ... + 24928.

It is an arithmetic number, because the mean of its divisors is an integer number (11689200).

Almost surely, 2^161251651 is an apocalyptic number.

161251651 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161251651 is a deficient number, since it is larger than the sum of its proper divisors (25775549).

161251651 is a wasteful number, since it uses less digits than its factorization.

161251651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7770.

The product of its digits is 1800, while the sum is 28.

The square root of 161251651 is about 12698.4901070954. The cubic root of 161251651 is about 544.2954743506.

The spelling of 161251651 in words is "one hundred sixty-one million, two hundred fifty-one thousand, six hundred fifty-one".