161192021 has 4 divisors (see below), whose sum is σ = 161217792. Its totient is φ = 161166252.

The previous prime is 161191937. The next prime is 161192023. The reversal of 161192021 is 120291161.

It is a happy number.

161192021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 161192021 - 2¹⁸ = 160929877 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161192023) 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, 3146 + ... + 18228.

It is an arithmetic number, because the mean of its divisors is an integer number (40304448).

Almost surely, 2^161192021 is an apocalyptic number.

It is an amenable number.

161192021 is a deficient number, since it is larger than the sum of its proper divisors (25771).

161192021 is a wasteful number, since it uses less digits than its factorization.

161192021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25770.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 161192021 is about 12696.1419730562. The cubic root of 161192021 is about 544.2283735582.

The spelling of 161192021 in words is "one hundred sixty-one million, one hundred ninety-two thousand, twenty-one".