161636438 has 4 divisors (see below), whose sum is σ = 242454660. Its totient is φ = 80818218.

The previous prime is 161636413. The next prime is 161636467. The reversal of 161636438 is 834636161.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×161636438² = 52252676178655688, 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 (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40409108 + ... + 40409111.

It is an arithmetic number, because the mean of its divisors is an integer number (60613665).

Almost surely, 2^161636438 is an apocalyptic number.

161636438 is a deficient number, since it is larger than the sum of its proper divisors (80818222).

161636438 is an equidigital number, since it uses as much as digits as its factorization.

161636438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80818221.

The product of its digits is 62208, while the sum is 38.

The square root of 161636438 is about 12713.6319751674. The cubic root of 161636438 is about 544.7280724077.

The spelling of 161636438 in words is "one hundred sixty-one million, six hundred thirty-six thousand, four hundred thirty-eight".