21461519 has 4 divisors (see below), whose sum is σ = 21517080. Its totient is φ = 21405960.

The previous prime is 21461467. The next prime is 21461521. The reversal of 21461519 is 91516412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21461519 is a prime.

It is a super-2 number, since 2×21461519² = 921193595574722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21461491 and 21461500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21461719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27197 + ... + 27974.

It is an arithmetic number, because the mean of its divisors is an integer number (5379270).

Almost surely, 2^21461519 is an apocalyptic number.

21461519 is a deficient number, since it is larger than the sum of its proper divisors (55561).

21461519 is an equidigital number, since it uses as much as digits as its factorization.

21461519 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55560.

The product of its digits is 2160, while the sum is 29.

The square root of 21461519 is about 4632.6578764247. The cubic root of 21461519 is about 277.8988944482.

The spelling of 21461519 in words is "twenty-one million, four hundred sixty-one thousand, five hundred nineteen".