157828621 has 4 divisors (see below), whose sum is σ = 159276700. Its totient is φ = 156380544.

The previous prime is 157828613. The next prime is 157828637. The reversal of 157828621 is 126828751.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45765225 + 112063396 = 6765^2 + 10586^2 .

It is a cyclic number.

It is not a de Polignac number, because 157828621 - 2³ = 157828613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157828661) 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 3 ways as a sum of consecutive naturals, for example, 723876 + ... + 724093.

It is an arithmetic number, because the mean of its divisors is an integer number (39819175).

Almost surely, 2^157828621 is an apocalyptic number.

It is an amenable number.

157828621 is a deficient number, since it is larger than the sum of its proper divisors (1448079).

157828621 is a wasteful number, since it uses less digits than its factorization.

157828621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1448078.

The product of its digits is 53760, while the sum is 40.

The square root of 157828621 is about 12562.9861497973. The cubic root of 157828621 is about 540.4164836817.

The spelling of 157828621 in words is "one hundred fifty-seven million, eight hundred twenty-eight thousand, six hundred twenty-one".