21357502 has 4 divisors (see below), whose sum is σ = 32036256. Its totient is φ = 10678750.

The previous prime is 21357499. The next prime is 21357509. The reversal of 21357502 is 20575312.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21357502² = 912285783360008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21357509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5339374 + ... + 5339377.

It is an arithmetic number, because the mean of its divisors is an integer number (8009064).

Almost surely, 2^21357502 is an apocalyptic number.

21357502 is a deficient number, since it is larger than the sum of its proper divisors (10678754).

21357502 is a wasteful number, since it uses less digits than its factorization.

21357502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10678753.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 21357502 is about 4621.4177478345. The cubic root of 21357502 is about 277.4492053229.

The spelling of 21357502 in words is "twenty-one million, three hundred fifty-seven thousand, five hundred two".