21256154 has 8 divisors (see below), whose sum is σ = 33759828. Its totient is φ = 10002880.

The previous prime is 21256153. The next prime is 21256229. The reversal of 21256154 is 45165212.

It can be written as a sum of positive squares in 2 ways, for example, as 21114025 + 142129 = 4595^2 + 377^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21256153) 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 3 ways as a sum of consecutive naturals, for example, 312557 + ... + 312624.

Almost surely, 2^21256154 is an apocalyptic number.

21256154 is a deficient number, since it is larger than the sum of its proper divisors (12503674).

21256154 is a wasteful number, since it uses less digits than its factorization.

21256154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625200.

The product of its digits is 2400, while the sum is 26.

The square root of 21256154 is about 4610.4396753455. The cubic root of 21256154 is about 277.0096483409.

The spelling of 21256154 in words is "twenty-one million, two hundred fifty-six thousand, one hundred fifty-four".