21256893485 has 4 divisors (see below), whose sum is σ = 25508272188. Its totient is φ = 17005514784.

The previous prime is 21256893467. The next prime is 21256893491. The reversal of 21256893485 is 58439865212.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9492020329 + 11764873156 = 97427^2 + 108466^2 .

It is a cyclic number.

It is not a de Polignac number, because 21256893485 - 2¹⁴ = 21256877101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2125689344 + ... + 2125689353.

It is an arithmetic number, because the mean of its divisors is an integer number (6377068047).

Almost surely, 2^21256893485 is an apocalyptic number.

It is an amenable number.

21256893485 is a deficient number, since it is larger than the sum of its proper divisors (4251378703).

21256893485 is an equidigital number, since it uses as much as digits as its factorization.

21256893485 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4251378702.

The product of its digits is 4147200, while the sum is 53.

The spelling of 21256893485 in words is "twenty-one billion, two hundred fifty-six million, eight hundred ninety-three thousand, four hundred eighty-five".