161554443421 has 8 divisors (see below), whose sum is σ = 184861880640. Its totient is φ = 138304063968.

The previous prime is 161554443419. The next prime is 161554443461. The reversal of 161554443421 is 124344455161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 161554443421 - 2¹ = 161554443419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161554443461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14258371 + ... + 14269696.

It is an arithmetic number, because the mean of its divisors is an integer number (23107735080).

Almost surely, 2^161554443421 is an apocalyptic number.

It is an amenable number.

161554443421 is a deficient number, since it is larger than the sum of its proper divisors (23307437219).

161554443421 is an equidigital number, since it uses as much as digits as its factorization.

161554443421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28528883.

The product of its digits is 230400, while the sum is 40.

Adding to 161554443421 its reverse (124344455161), we get a palindrome (285898898582).

The spelling of 161554443421 in words is "one hundred sixty-one billion, five hundred fifty-four million, four hundred forty-three thousand, four hundred twenty-one".