161400289440 has 384 divisors, whose sum is σ = 563187002112. Its totient is φ = 38606929920.

The previous prime is 161400289411. The next prime is 161400289459. The reversal of 161400289440 is 44982004161.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 35384760 + ... + 35389320.

It is an arithmetic number, because the mean of its divisors is an integer number (1466632818).

Almost surely, 2^161400289440 is an apocalyptic number.

161400289440 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 161400289440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281593501056).

161400289440 is an abundant number, since it is smaller than the sum of its proper divisors (401786712672).

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

161400289440 is a wasteful number, since it uses less digits than its factorization.

161400289440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4752 (or 4744 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The spelling of 161400289440 in words is "one hundred sixty-one billion, four hundred million, two hundred eighty-nine thousand, four hundred forty".