161651839 has 2 divisors, whose sum is σ = 161651840. Its totient is φ = 161651838.

The previous prime is 161651821. The next prime is 161651869. The reversal of 161651839 is 938156161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161651839 - 2²⁷ = 27434111 is a prime.

It is a super-2 number, since 2×161651839² = 52262634104163842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161651869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80825919 + 80825920.

It is an arithmetic number, because the mean of its divisors is an integer number (80825920).

Almost surely, 2^161651839 is an apocalyptic number.

161651839 is a deficient number, since it is larger than the sum of its proper divisors (1).

161651839 is an equidigital number, since it uses as much as digits as its factorization.

161651839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38880, while the sum is 40.

The square root of 161651839 is about 12714.2376491868. The cubic root of 161651839 is about 544.7453727365.

The spelling of 161651839 in words is "one hundred sixty-one million, six hundred fifty-one thousand, eight hundred thirty-nine".