161451380520 has 640 divisors, whose sum is σ = 602487072000. Its totient is φ = 38593843200.

The previous prime is 161451380483. The next prime is 161451380537. The reversal of 161451380520 is 25083154161.

161451380520 is a `hidden beast` number, since 1 + 6 + 1 + 4 + 51 + 3 + 80 + 520 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 143003316 + ... + 143004444.

It is an arithmetic number, because the mean of its divisors is an integer number (941386050).

Almost surely, 2^161451380520 is an apocalyptic number.

161451380520 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 161451380520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301243536000).

161451380520 is an abundant number, since it is smaller than the sum of its proper divisors (441035691480).

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

161451380520 is a wasteful number, since it uses less digits than its factorization.

161451380520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1295 (or 1282 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The spelling of 161451380520 in words is "one hundred sixty-one billion, four hundred fifty-one million, three hundred eighty thousand, five hundred twenty".