21352157 has 8 divisors (see below), whose sum is σ = 21606816. Its totient is φ = 21099312.

The previous prime is 21352139. The next prime is 21352183. The reversal of 21352157 is 75125312.

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 21352157 - 2²⁰ = 20303581 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 (21352127) 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, 47978 + ... + 48420.

It is an arithmetic number, because the mean of its divisors is an integer number (2700852).

Almost surely, 2^21352157 is an apocalyptic number.

It is an amenable number.

21352157 is a deficient number, since it is larger than the sum of its proper divisors (254659).

21352157 is a wasteful number, since it uses less digits than its factorization.

21352157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 907.

The product of its digits is 2100, while the sum is 26.

The square root of 21352157 is about 4620.8394259052. The cubic root of 21352157 is about 277.4260582693.

Adding to 21352157 its reverse (75125312), we get a palindrome (96477469).

The spelling of 21352157 in words is "twenty-one million, three hundred fifty-two thousand, one hundred fifty-seven".