21256485 has 16 divisors (see below), whose sum is σ = 35489664. Its totient is φ = 10843712.

The previous prime is 21256481. The next prime is 21256517. The reversal of 21256485 is 58465212.

It is a cyclic number.

It is not a de Polignac number, because 21256485 - 2² = 21256481 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21256481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30462 + ... + 31151.

It is an arithmetic number, because the mean of its divisors is an integer number (2218104).

Almost surely, 2^21256485 is an apocalyptic number.

It is an amenable number.

21256485 is a deficient number, since it is larger than the sum of its proper divisors (14233179).

21256485 is a wasteful number, since it uses less digits than its factorization.

21256485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61644.

The product of its digits is 19200, while the sum is 33.

The square root of 21256485 is about 4610.4755719991. The cubic root of 21256485 is about 277.0110861946.

The spelling of 21256485 in words is "twenty-one million, two hundred fifty-six thousand, four hundred eighty-five".