161971453163520 has 8640 divisors, whose sum is σ = 848096297848800. Its totient is φ = 29028542054400.

The previous prime is 161971453163453. The next prime is 161971453163591. The reversal of 161971453163520 is 25361354179161.

161971453163520 is a `hidden beast` number, since 1 + 6 + 1 + 9 + 7 + 1 + 4 + 53 + 1 + 63 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (8640).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 719 ways as a sum of consecutive naturals, for example, 5224885585905 + ... + 5224885585935.

Almost surely, 2^{161971453163520} is an apocalyptic number.

161971453163520 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 161971453163520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (424048148924400).

161971453163520 is an abundant number, since it is smaller than the sum of its proper divisors (686124844685280).

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

161971453163520 is a wasteful number, since it uses less digits than its factorization.

161971453163520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 4082400, while the sum is 54.

The spelling of 161971453163520 in words is "one hundred sixty-one trillion, nine hundred seventy-one billion, four hundred fifty-three million, one hundred sixty-three thousand, five hundred twenty".