157242421 has 36 divisors (see below), whose sum is σ = 197993376. Its totient is φ = 124259520.

The previous prime is 157242413. The next prime is 157242431. The reversal of 157242421 is 124242751.

It is not a de Polignac number, because 157242421 - 2³ = 157242413 is a prime.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 157242421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157242431) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1894446 + ... + 1894528.

It is an arithmetic number, because the mean of its divisors is an integer number (5499816).

Almost surely, 2^157242421 is an apocalyptic number.

It is an amenable number.

157242421 is a deficient number, since it is larger than the sum of its proper divisors (40750955).

157242421 is an equidigital number, since it uses as much as digits as its factorization.

157242421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 154 counting only the distinct ones).

The product of its digits is 4480, while the sum is 28.

The square root of 157242421 is about 12539.6340058233. The cubic root of 157242421 is about 539.7465900610.

It can be divided in two parts, 15724 and 2421, that added together give a triangular number (18145 = T₁₉₀).

The spelling of 157242421 in words is "one hundred fifty-seven million, two hundred forty-two thousand, four hundred twenty-one".