161937405 has 54 divisors (see below), whose sum is σ = 327727998. Its totient is φ = 73755360.

The previous prime is 161937401. The next prime is 161937407. The reversal of 161937405 is 504739161.

161937405 is a `hidden beast` number, since 1 + 619 + 37 + 4 + 0 + 5 = 666.

It can be written as a sum of positive squares in only one way, i.e., 129549924 + 32387481 = 11382^2 + 5691^2 .

It is not a de Polignac number, because 161937405 - 2² = 161937401 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161937405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161937401) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 597420 + ... + 597690.

It is an arithmetic number, because the mean of its divisors is an integer number (6069037).

Almost surely, 2^161937405 is an apocalyptic number.

161937405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161937405 is an abundant number, since it is smaller than the sum of its proper divisors (165790593).

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

161937405 is an equidigital number, since it uses as much as digits as its factorization.

161937405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The square root of 161937405 is about 12725.4628599513. The cubic root of 161937405 is about 545.0659572840.

The spelling of 161937405 in words is "one hundred sixty-one million, nine hundred thirty-seven thousand, four hundred five".