161981542 has 16 divisors (see below), whose sum is σ = 257517792. Its totient is φ = 76151680.

The previous prime is 161981537. The next prime is 161981563. The reversal of 161981542 is 245189161.

161981542 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49167 + ... + 52357.

It is an arithmetic number, because the mean of its divisors is an integer number (16094862).

Almost surely, 2^161981542 is an apocalyptic number.

161981542 is a deficient number, since it is larger than the sum of its proper divisors (95536250).

161981542 is a wasteful number, since it uses less digits than its factorization.

161981542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4703.

The product of its digits is 17280, while the sum is 37.

The square root of 161981542 is about 12727.1969419822. The cubic root of 161981542 is about 545.1154731053.

The spelling of 161981542 in words is "one hundred sixty-one million, nine hundred eighty-one thousand, five hundred forty-two".