161606638 has 8 divisors (see below), whose sum is σ = 242471088. Its totient is φ = 80782944.

The previous prime is 161606617. The next prime is 161606651. The reversal of 161606638 is 836606161.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161606638² = 52233410891326088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161606597 and 161606606.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3295 + ... + 18277.

It is an arithmetic number, because the mean of its divisors is an integer number (30308886).

Almost surely, 2^161606638 is an apocalyptic number.

161606638 is a deficient number, since it is larger than the sum of its proper divisors (80864450).

161606638 is a wasteful number, since it uses less digits than its factorization.

161606638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20378.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 161606638 is about 12712.4599507727. The cubic root of 161606638 is about 544.6945942010.

The spelling of 161606638 in words is "one hundred sixty-one million, six hundred six thousand, six hundred thirty-eight".