21256467 has 8 divisors (see below), whose sum is σ = 28466640. Its totient is φ = 14108640.

The previous prime is 21256457. The next prime is 21256471. The reversal of 21256467 is 76465212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21256467 - 2²³ = 12867859 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (21256447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14784 + ... + 16157.

It is an arithmetic number, because the mean of its divisors is an integer number (3558330).

Almost surely, 2^21256467 is an apocalyptic number.

21256467 is a deficient number, since it is larger than the sum of its proper divisors (7210173).

21256467 is a wasteful number, since it uses less digits than its factorization.

21256467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31173.

The product of its digits is 20160, while the sum is 33.

The square root of 21256467 is about 4610.4736199224. The cubic root of 21256467 is about 277.0110080035.

The spelling of 21256467 in words is "twenty-one million, two hundred fifty-six thousand, four hundred sixty-seven".