161451777631 has 8 divisors (see below), whose sum is σ = 162078083264. Its totient is φ = 160825785120.

The previous prime is 161451777533. The next prime is 161451777637. The reversal of 161451777631 is 136777154161.

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-161451777631 is a prime.

It is a super-2 number, since 2×161451777631² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161451777637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 982741 + ... + 1135201.

It is an arithmetic number, because the mean of its divisors is an integer number (20259760408).

Almost surely, 2^161451777631 is an apocalyptic number.

161451777631 is a deficient number, since it is larger than the sum of its proper divisors (626305633).

161451777631 is a wasteful number, since it uses less digits than its factorization.

161451777631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156561.

The product of its digits is 740880, while the sum is 49.

The spelling of 161451777631 in words is "one hundred sixty-one billion, four hundred fifty-one million, seven hundred seventy-seven thousand, six hundred thirty-one".