21519254 has 4 divisors (see below), whose sum is σ = 32278884. Its totient is φ = 10759626.

The previous prime is 21519227. The next prime is 21519293. The reversal of 21519254 is 45291512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5379812 + ... + 5379815.

It is an arithmetic number, because the mean of its divisors is an integer number (8069721).

Almost surely, 2^21519254 is an apocalyptic number.

21519254 is a deficient number, since it is larger than the sum of its proper divisors (10759630).

21519254 is a wasteful number, since it uses less digits than its factorization.

21519254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10759629.

The product of its digits is 3600, while the sum is 29.

The square root of 21519254 is about 4638.8849953410. The cubic root of 21519254 is about 278.1478691627.

The spelling of 21519254 in words is "twenty-one million, five hundred nineteen thousand, two hundred fifty-four".