157721814433 has 4 divisors (see below), whose sum is σ = 158115136068. Its totient is φ = 157328492800.

The previous prime is 157721814389. The next prime is 157721814449. The reversal of 157721814433 is 334418127751.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 334418127751 = 51263 ⋅6523577.

It can be written as a sum of positive squares in 2 ways, for example, as 143810083729 + 13911730704 = 379223^2 + 117948^2 .

It is a cyclic number.

It is not a de Polignac number, because 157721814433 - 2²⁹ = 157184943521 is a prime.

It is a super-2 number, since 2×157721814433² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157721814463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196660216 + ... + 196661017.

It is an arithmetic number, because the mean of its divisors is an integer number (39528784017).

Almost surely, 2^157721814433 is an apocalyptic number.

It is an amenable number.

157721814433 is a deficient number, since it is larger than the sum of its proper divisors (393321635).

157721814433 is an equidigital number, since it uses as much as digits as its factorization.

157721814433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 393321634.

The product of its digits is 564480, while the sum is 46.

The spelling of 157721814433 in words is "one hundred fifty-seven billion, seven hundred twenty-one million, eight hundred fourteen thousand, four hundred thirty-three".