21390519407 has 4 divisors (see below), whose sum is σ = 21423581136. Its totient is φ = 21357457680.

The previous prime is 21390519389. The next prime is 21390519457. The reversal of 21390519407 is 70491509312.

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

It is a cyclic number.

It is not a de Polignac number, because 21390519407 - 2⁸ = 21390519151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21390519457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16529894 + ... + 16531187.

It is an arithmetic number, because the mean of its divisors is an integer number (5355895284).

Almost surely, 2^21390519407 is an apocalyptic number.

21390519407 is a deficient number, since it is larger than the sum of its proper divisors (33061729).

21390519407 is an equidigital number, since it uses as much as digits as its factorization.

21390519407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33061728.

The product of its (nonzero) digits is 68040, while the sum is 41.

The spelling of 21390519407 in words is "twenty-one billion, three hundred ninety million, five hundred nineteen thousand, four hundred seven".