21170452157 has 8 divisors (see below), whose sum is σ = 21533597280. Its totient is φ = 20807451280.

The previous prime is 21170452117. The next prime is 21170452159. The reversal of 21170452157 is 75125407112.

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 21170452157 - 2⁸ = 21170451901 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 (21170452159) 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, 284138 + ... + 350820.

It is an arithmetic number, because the mean of its divisors is an integer number (2691699660).

Almost surely, 2^21170452157 is an apocalyptic number.

It is an amenable number.

21170452157 is a deficient number, since it is larger than the sum of its proper divisors (363145123).

21170452157 is an equidigital number, since it uses as much as digits as its factorization.

21170452157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72123.

The product of its (nonzero) digits is 19600, while the sum is 35.

Adding to 21170452157 its reverse (75125407112), we get a palindrome (96295859269).

The spelling of 21170452157 in words is "twenty-one billion, one hundred seventy million, four hundred fifty-two thousand, one hundred fifty-seven".