161640542 has 16 divisors (see below), whose sum is σ = 280895712. Its totient is φ = 68325120.

The previous prime is 161640529. The next prime is 161640587. The reversal of 161640542 is 245046161.

It is a super-2 number, since 2×161640542² = 52255329636107528, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 78059 + ... + 80102.

It is an arithmetic number, because the mean of its divisors is an integer number (17555982).

Almost surely, 2^161640542 is an apocalyptic number.

161640542 is a deficient number, since it is larger than the sum of its proper divisors (119255170).

161640542 is a wasteful number, since it uses less digits than its factorization.

161640542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158243.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 161640542 is about 12713.7933757003. The cubic root of 161640542 is about 544.7326826410.

The spelling of 161640542 in words is "one hundred sixty-one million, six hundred forty thousand, five hundred forty-two".