161625784320 has 1920 divisors, whose sum is σ = 782129940480. Its totient is φ = 30576476160.

The previous prime is 161625784319. The next prime is 161625784367. The reversal of 161625784320 is 23487526161.

161625784320 is a `hidden beast` number, since 1 + 6 + 16 + 2 + 578 + 43 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a super-2 number, since 2×161625784320² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2214051804 + ... + 2214051876.

It is an arithmetic number, because the mean of its divisors is an integer number (407359344).

Almost surely, 2^161625784320 is an apocalyptic number.

161625784320 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 161625784320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391064970240).

161625784320 is an abundant number, since it is smaller than the sum of its proper divisors (620504156160).

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

161625784320 is a wasteful number, since it uses less digits than its factorization.

161625784320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 161625784320 in words is "one hundred sixty-one billion, six hundred twenty-five million, seven hundred eighty-four thousand, three hundred twenty".