157489921 has 8 divisors (see below), whose sum is σ = 166946184. Its totient is φ = 148055040.

The previous prime is 157489909. The next prime is 157489991. The reversal of 157489921 is 129984751.

It can be written as a sum of positive squares in 4 ways, for example, as 5313025 + 152176896 = 2305^2 + 12336^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 157489921 - 2¹³ = 157481729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157489991) 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 7 ways as a sum of consecutive naturals, for example, 11341 + ... + 21061.

It is an arithmetic number, because the mean of its divisors is an integer number (20868273).

Almost surely, 2^157489921 is an apocalyptic number.

It is an amenable number.

157489921 is a deficient number, since it is larger than the sum of its proper divisors (9456263).

157489921 is an equidigital number, since it uses as much as digits as its factorization.

157489921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10691.

The product of its digits is 181440, while the sum is 46.

The square root of 157489921 is about 12549.4988346149. The cubic root of 157489921 is about 540.0296291470.

The spelling of 157489921 in words is "one hundred fifty-seven million, four hundred eighty-nine thousand, nine hundred twenty-one".