161578780 has 36 divisors (see below), whose sum is σ = 370594728. Its totient is φ = 58687360.

The previous prime is 161578777. The next prime is 161578783. The reversal of 161578780 is 87875161.

It is an interprime number because it is at equal distance from previous prime (161578777) and next prime (161578783).

It is a super-2 number, since 2×161578780² = 52215404292576800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161578783) 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, 188112 + ... + 188968.

It is an arithmetic number, because the mean of its divisors is an integer number (10294298).

Almost surely, 2^161578780 is an apocalyptic number.

161578780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161578780 is an abundant number, since it is smaller than the sum of its proper divisors (209015948).

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

161578780 is an equidigital number, since it uses as much as digits as its factorization.

161578780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1734 (or 875 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 43.

The square root of 161578780 is about 12711.3642068820. The cubic root of 161578780 is about 544.6632939726.

The spelling of 161578780 in words is "one hundred sixty-one million, five hundred seventy-eight thousand, seven hundred eighty".