157421 has 6 divisors (see below), whose sum is σ = 173166. Its totient is φ = 143000.

The previous prime is 157411. The next prime is 157427. The reversal of 157421 is 124751.

It can be written as a sum of positive squares in only one way, i.e., 81796 + 75625 = 286^2 + 275^2 .

It is a de Polignac number, because none of the positive numbers 2^k-157421 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 157393 and 157402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157427) 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 5 ways as a sum of consecutive naturals, for example, 530 + ... + 771.

It is an arithmetic number, because the mean of its divisors is an integer number (28861).

2¹⁵⁷⁴²¹ is an apocalyptic number.

157421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

157421 is a deficient number, since it is larger than the sum of its proper divisors (15745).

157421 is a wasteful number, since it uses less digits than its factorization.

157421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1312 counting only the distinct ones).

The product of its digits is 280, while the sum is 20.

The square root of 157421 is about 396.7631535312. The cubic root of 157421 is about 53.9950841433.

The spelling of 157421 in words is "one hundred fifty-seven thousand, four hundred twenty-one".