21101157 has 24 divisors (see below), whose sum is σ = 38001600. Its totient is φ = 10961280.

The previous prime is 21101123. The next prime is 21101207. The reversal of 21101157 is 75110112.

It is a happy number.

It is not a de Polignac number, because 21101157 - 2⁸ = 21100901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101257) 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 23 ways as a sum of consecutive naturals, for example, 14532 + ... + 15917.

It is an arithmetic number, because the mean of its divisors is an integer number (1583400).

Almost surely, 2^21101157 is an apocalyptic number.

It is an amenable number.

21101157 is a deficient number, since it is larger than the sum of its proper divisors (16900443).

21101157 is a wasteful number, since it uses less digits than its factorization.

21101157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30473 (or 30470 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 18.

The square root of 21101157 is about 4593.5995689655. The cubic root of 21101157 is about 276.3346994978.

Adding to 21101157 its reverse (75110112), we get a palindrome (96211269).

The spelling of 21101157 in words is "twenty-one million, one hundred one thousand, one hundred fifty-seven".