161213520 has 160 divisors (see below), whose sum is σ = 543215232. Its totient is φ = 39315456.

The previous prime is 161213513. The next prime is 161213527. The reversal of 161213520 is 25312161.

161213520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (161213513) and next prime (161213527).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161213527) 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, 508402 + ... + 508718.

Almost surely, 2^161213520 is an apocalyptic number.

161213520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161213520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271607616).

161213520 is an abundant number, since it is smaller than the sum of its proper divisors (382001712).

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

161213520 is a wasteful number, since it uses less digits than its factorization.

161213520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509 (or 503 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 161213520 is about 12696.9886193538. The cubic root of 161213520 is about 544.2525679850.

Adding to 161213520 its reverse (25312161), we get a palindrome (186525681).

The spelling of 161213520 in words is "one hundred sixty-one million, two hundred thirteen thousand, five hundred twenty".