158721638401 has 4 divisors (see below), whose sum is σ = 158722606512. Its totient is φ = 158720670292.

The previous prime is 158721638353. The next prime is 158721638441. The reversal of 158721638401 is 104836127851.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-158721638401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (158721638441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170371 + ... + 588616.

It is an arithmetic number, because the mean of its divisors is an integer number (39680651628).

Almost surely, 2^158721638401 is an apocalyptic number.

It is an amenable number.

158721638401 is a deficient number, since it is larger than the sum of its proper divisors (968111).

158721638401 is an equidigital number, since it uses as much as digits as its factorization.

158721638401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 968110.

The product of its (nonzero) digits is 322560, while the sum is 46.

The spelling of 158721638401 in words is "one hundred fifty-eight billion, seven hundred twenty-one million, six hundred thirty-eight thousand, four hundred one".