21257202 has 16 divisors (see below), whose sum is σ = 42762240. Its totient is φ = 7044432.

The previous prime is 21257189. The next prime is 21257209. The reversal of 21257202 is 20275212.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21257209) 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, 9202 + ... + 11277.

It is an arithmetic number, because the mean of its divisors is an integer number (2672640).

Almost surely, 2^21257202 is an apocalyptic number.

21257202 is an abundant number, since it is smaller than the sum of its proper divisors (21505038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21257202 is a wasteful number, since it uses less digits than its factorization.

21257202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20657.

The product of its (nonzero) digits is 560, while the sum is 21.

The square root of 21257202 is about 4610.5533290485. The cubic root of 21257202 is about 277.0142007690.

The spelling of 21257202 in words is "twenty-one million, two hundred fifty-seven thousand, two hundred two".