161573540 has 12 divisors (see below), whose sum is σ = 339304476. Its totient is φ = 64629408.

The previous prime is 161573539. The next prime is 161573563. The reversal of 161573540 is 45375161.

It can be written as a sum of positive squares in 2 ways, for example, as 125260864 + 36312676 = 11192^2 + 6026^2 .

It is a super-2 number, since 2×161573540² = 52212017656263200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 161573497 and 161573506.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4039319 + ... + 4039358.

It is an arithmetic number, because the mean of its divisors is an integer number (28275373).

Almost surely, 2^161573540 is an apocalyptic number.

161573540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161573540 is an abundant number, since it is smaller than the sum of its proper divisors (177730936).

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

161573540 is a wasteful number, since it uses less digits than its factorization.

161573540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8078686 (or 8078684 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 161573540 is about 12711.1580904338. The cubic root of 161573540 is about 544.6574060986.

The spelling of 161573540 in words is "one hundred sixty-one million, five hundred seventy-three thousand, five hundred forty".