157838549521 has 3 divisors (see below), whose sum is σ = 157838946811. Its totient is φ = 157838152232.

The previous prime is 157838549489. The next prime is 157838549551. The reversal of 157838549521 is 125945838751.

The square root of 157838549521 is 397289.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 125945838751 = 74101 ⋅1699651.

It can be written as a sum of positive squares in only one way, i.e., 96572399121 + 61266150400 = 310761^2 + 247520^2 .

It is not a de Polignac number, because 157838549521 - 2⁵ = 157838549489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157838549551) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 198645 + ... + 595933.

Almost surely, 2^157838549521 is an apocalyptic number.

157838549521 is the 397289-th square number.

157838549521 is the 198645-th centered octagonal number.

It is an amenable number.

157838549521 is a deficient number, since it is larger than the sum of its proper divisors (397290).

157838549521 is an frugal number, since it uses more digits than its factorization.

157838549521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794578 (or 397289 counting only the distinct ones).

The product of its digits is 12096000, while the sum is 58.

The spelling of 157838549521 in words is "one hundred fifty-seven billion, eight hundred thirty-eight million, five hundred forty-nine thousand, five hundred twenty-one".