21386157 has 8 divisors (see below), whose sum is σ = 30708384. Its totient is φ = 13160688.

The previous prime is 21386149. The next prime is 21386203. The reversal of 21386157 is 75168312.

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

It is not a de Polignac number, because 21386157 - 2³ = 21386149 is a prime.

It is a super-2 number, since 2×21386157² = 914735422457298, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21386117) 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, 274143 + ... + 274220.

It is an arithmetic number, because the mean of its divisors is an integer number (3838548).

Almost surely, 2^21386157 is an apocalyptic number.

It is an amenable number.

21386157 is a deficient number, since it is larger than the sum of its proper divisors (9322227).

21386157 is a wasteful number, since it uses less digits than its factorization.

21386157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548379.

The product of its digits is 10080, while the sum is 33.

The square root of 21386157 is about 4624.5169477471. The cubic root of 21386157 is about 277.5732328431.

The spelling of 21386157 in words is "twenty-one million, three hundred eighty-six thousand, one hundred fifty-seven".