161623649 has 4 divisors (see below), whose sum is σ = 176316720. Its totient is φ = 146930580.

The previous prime is 161623639. The next prime is 161623661. The reversal of 161623649 is 946326161.

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.

It is a cyclic number.

It is not a de Polignac number, because 161623649 - 2²⁰ = 160575073 is a prime.

It is a super-2 number, since 2×161623649² = 52244407832150402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161623639) 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, 7346519 + ... + 7346540.

It is an arithmetic number, because the mean of its divisors is an integer number (44079180).

Almost surely, 2^161623649 is an apocalyptic number.

It is an amenable number.

161623649 is a deficient number, since it is larger than the sum of its proper divisors (14693071).

161623649 is a wasteful number, since it uses less digits than its factorization.

161623649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14693070.

The product of its digits is 46656, while the sum is 38.

The square root of 161623649 is about 12713.1290011547. The cubic root of 161623649 is about 544.7137053686.

The spelling of 161623649 in words is "one hundred sixty-one million, six hundred twenty-three thousand, six hundred forty-nine".