161571400 has 48 divisors (see below), whose sum is σ = 397759140. Its totient is φ = 60825600.

The previous prime is 161571379. The next prime is 161571407. The reversal of 161571400 is 4175161.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 117029124 + 44542276 = 10818^2 + 6674^2 .

It is a super-2 number, since 2×161571400² = 52210634595920000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161571407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20361 + ... + 27160.

Almost surely, 2^161571400 is an apocalyptic number.

161571400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161571400 is an abundant number, since it is smaller than the sum of its proper divisors (236187740).

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

161571400 is a wasteful number, since it uses less digits than its factorization.

161571400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47554 (or 47545 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 161571400 is about 12711.0739121445. The cubic root of 161571400 is about 544.6550014722.

The spelling of 161571400 in words is "one hundred sixty-one million, five hundred seventy-one thousand, four hundred".