161477731 has 8 divisors (see below), whose sum is σ = 166387104. Its totient is φ = 156597120.

The previous prime is 161477683. The next prime is 161477753. The reversal of 161477731 is 137774161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161477731 is a prime.

It is a super-2 number, since 2×161477731² = 52150115217816722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161477761) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 4491 + ... + 18523.

It is an arithmetic number, because the mean of its divisors is an integer number (20798388).

Almost surely, 2^161477731 is an apocalyptic number.

161477731 is a deficient number, since it is larger than the sum of its proper divisors (4909373).

161477731 is a wasteful number, since it uses less digits than its factorization.

161477731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14381.

The product of its digits is 24696, while the sum is 37.

The square root of 161477731 is about 12707.3888348472. The cubic root of 161477731 is about 544.5497288159.

The spelling of 161477731 in words is "one hundred sixty-one million, four hundred seventy-seven thousand, seven hundred thirty-one".