161645551404 has 96 divisors (see below), whose sum is σ = 384438163200. Its totient is φ = 52855545600.

The previous prime is 161645551393. The next prime is 161645551409. The reversal of 161645551404 is 404155546161.

It is a super-2 number, since 2×161645551404² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161645551409) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 144713454 + ... + 144714570.

It is an arithmetic number, because the mean of its divisors is an integer number (4004564200).

Almost surely, 2^161645551404 is an apocalyptic number.

It is an amenable number.

161645551404 is an abundant number, since it is smaller than the sum of its proper divisors (222792611796).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161645551404 is a wasteful number, since it uses less digits than its factorization.

161645551404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2223 (or 2221 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 42.

The spelling of 161645551404 in words is "one hundred sixty-one billion, six hundred forty-five million, five hundred fifty-one thousand, four hundred four".