157721598221 has 32 divisors (see below), whose sum is σ = 180713410560. Its totient is φ = 136352937600.

The previous prime is 157721598197. The next prime is 157721598253. The reversal of 157721598221 is 122895127751.

It is not a de Polignac number, because 157721598221 - 2¹⁰ = 157721597197 is a prime.

It is a super-2 number, since 2×157721598221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 157721598221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157721594221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4930946 + ... + 4962828.

It is an arithmetic number, because the mean of its divisors is an integer number (5647294080).

Almost surely, 2^157721598221 is an apocalyptic number.

157721598221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

157721598221 is a deficient number, since it is larger than the sum of its proper divisors (22991812339).

157721598221 is a wasteful number, since it uses less digits than its factorization.

157721598221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32177.

The product of its digits is 705600, while the sum is 50.

The spelling of 157721598221 in words is "one hundred fifty-seven billion, seven hundred twenty-one million, five hundred ninety-eight thousand, two hundred twenty-one".