21254919 has 16 divisors (see below), whose sum is σ = 32459520. Its totient is φ = 12119040.

The previous prime is 21254903. The next prime is 21254923. The reversal of 21254919 is 91945212.

It is not a de Polignac number, because 21254919 - 2⁴ = 21254903 is a prime.

It is a super-2 number, since 2×21254919² = 903543163393122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21254919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21254929) 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, 12672 + ... + 14250.

It is an arithmetic number, because the mean of its divisors is an integer number (2028720).

Almost surely, 2^21254919 is an apocalyptic number.

21254919 is a deficient number, since it is larger than the sum of its proper divisors (11204601).

21254919 is a wasteful number, since it uses less digits than its factorization.

21254919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2230.

The product of its digits is 6480, while the sum is 33.

The square root of 21254919 is about 4610.3057382347. The cubic root of 21254919 is about 277.0042834076.

The spelling of 21254919 in words is "twenty-one million, two hundred fifty-four thousand, nine hundred nineteen".