157563721 has 8 divisors (see below), whose sum is σ = 180264960. Its totient is φ = 134910528.

The previous prime is 157563719. The next prime is 157563733. The reversal of 157563721 is 127365751.

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

It is a cyclic number.

It is not a de Polignac number, because 157563721 - 2¹ = 157563719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (157563761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4681 + ... + 18358.

It is an arithmetic number, because the mean of its divisors is an integer number (22533120).

Almost surely, 2^157563721 is an apocalyptic number.

It is an amenable number.

157563721 is a deficient number, since it is larger than the sum of its proper divisors (22701239).

157563721 is an equidigital number, since it uses as much as digits as its factorization.

157563721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24023.

The product of its digits is 44100, while the sum is 37.

The square root of 157563721 is about 12552.4388466943. The cubic root of 157563721 is about 540.1139688575.

The spelling of 157563721 in words is "one hundred fifty-seven million, five hundred sixty-three thousand, seven hundred twenty-one".