21257076 has 12 divisors (see below), whose sum is σ = 49599872. Its totient is φ = 7085688.

The previous prime is 21257059. The next prime is 21257077. The reversal of 21257076 is 67075212.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21257077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 885700 + ... + 885723.

Almost surely, 2^21257076 is an apocalyptic number.

It is an amenable number.

21257076 is an abundant number, since it is smaller than the sum of its proper divisors (28342796).

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

21257076 is a wasteful number, since it uses less digits than its factorization.

21257076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1771430 (or 1771428 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 21257076 is about 4610.5396647247. The cubic root of 21257076 is about 277.0136534430.

It can be divided in two parts, 2 and 1257076, that multiplied together give a palindrome (2514152).

The spelling of 21257076 in words is "twenty-one million, two hundred fifty-seven thousand, seventy-six".