161919537 has 32 divisors (see below), whose sum is σ = 240299136. Its totient is φ = 96345600.

The previous prime is 161919533. The next prime is 161919551. The reversal of 161919537 is 735919161.

It is not a de Polignac number, because 161919537 - 2² = 161919533 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161919533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 209083 + ... + 209855.

It is an arithmetic number, because the mean of its divisors is an integer number (7509348).

Almost surely, 2^161919537 is an apocalyptic number.

It is an amenable number.

161919537 is a deficient number, since it is larger than the sum of its proper divisors (78379599).

161919537 is a wasteful number, since it uses less digits than its factorization.

161919537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961.

The product of its digits is 51030, while the sum is 42.

The square root of 161919537 is about 12724.7607836061. The cubic root of 161919537 is about 545.0459092151.

The spelling of 161919537 in words is "one hundred sixty-one million, nine hundred nineteen thousand, five hundred thirty-seven".