157866821 has 8 divisors (see below), whose sum is σ = 182280000. Its totient is φ = 133918848.

The previous prime is 157866817. The next prime is 157866847. The reversal of 157866821 is 128668751.

It is a happy number.

157866821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 157866821 - 2² = 157866817 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157866521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115571 + ... + 116928.

It is an arithmetic number, because the mean of its divisors is an integer number (22785000).

Almost surely, 2^157866821 is an apocalyptic number.

It is an amenable number.

157866821 is a deficient number, since it is larger than the sum of its proper divisors (24413179).

157866821 is an equidigital number, since it uses as much as digits as its factorization.

157866821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 232603.

The product of its digits is 161280, while the sum is 44.

The square root of 157866821 is about 12564.5063969899. The cubic root of 157866821 is about 540.4600800084.

The spelling of 157866821 in words is "one hundred fifty-seven million, eight hundred sixty-six thousand, eight hundred twenty-one".