161807399 has 4 divisors (see below), whose sum is σ = 174254136. Its totient is φ = 149360664.

The previous prime is 161807389. The next prime is 161807413. The reversal of 161807399 is 993708161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993708161 = 13613 ⋅72997.

It is a cyclic number.

It is not a de Polignac number, because 161807399 - 2¹⁶ = 161741863 is a prime.

It is a super-2 number, since 2×161807399² = 52363268742290402, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161807389) 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, 6223349 + ... + 6223374.

It is an arithmetic number, because the mean of its divisors is an integer number (43563534).

Almost surely, 2^161807399 is an apocalyptic number.

161807399 is a deficient number, since it is larger than the sum of its proper divisors (12446737).

161807399 is a wasteful number, since it uses less digits than its factorization.

161807399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12446736.

The product of its (nonzero) digits is 81648, while the sum is 44.

The square root of 161807399 is about 12720.3537293583. The cubic root of 161807399 is about 544.9200556082.

The spelling of 161807399 in words is "one hundred sixty-one million, eight hundred seven thousand, three hundred ninety-nine".