161219697408 has 1152 divisors, whose sum is σ = 635765760000. Its totient is φ = 39036764160.

The previous prime is 161219697349. The next prime is 161219697433. The reversal of 161219697408 is 804796912161.

161219697408 is a `hidden beast` number, since 1 + 61 + 2 + 1 + 96 + 97 + 408 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 1082011318 + ... + 1082011466.

It is an arithmetic number, because the mean of its divisors is an integer number (551880000).

Almost surely, 2^161219697408 is an apocalyptic number.

161219697408 is a gapful number since it is divisible by the number (18) 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 161219697408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (317882880000).

161219697408 is an abundant number, since it is smaller than the sum of its proper divisors (474546062592).

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

161219697408 is a wasteful number, since it uses less digits than its factorization.

161219697408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318 (or 298 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 161219697408 in words is "one hundred sixty-one billion, two hundred nineteen million, six hundred ninety-seven thousand, four hundred eight".