157991477 has 4 divisors (see below), whose sum is σ = 180561696. Its totient is φ = 135421260.

The previous prime is 157991447. The next prime is 157991539. The reversal of 157991477 is 774199751.

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 an emirpimes, since its reverse is a distinct semiprime: 774199751 = 13 ⋅59553827.

It is a cyclic number.

It is not a de Polignac number, because 157991477 - 2¹² = 157987381 is a prime.

It is a super-2 number, since 2×157991477² = 49922613609283058, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157991437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11285099 + ... + 11285112.

It is an arithmetic number, because the mean of its divisors is an integer number (45140424).

Almost surely, 2^157991477 is an apocalyptic number.

It is an amenable number.

157991477 is a deficient number, since it is larger than the sum of its proper divisors (22570219).

157991477 is an equidigital number, since it uses as much as digits as its factorization.

157991477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22570218.

The product of its digits is 555660, while the sum is 50.

The square root of 157991477 is about 12569.4660586677. The cubic root of 157991477 is about 540.6022966487.

The spelling of 157991477 in words is "one hundred fifty-seven million, nine hundred ninety-one thousand, four hundred seventy-seven".