21915514783 has 2 divisors, whose sum is σ = 21915514784. Its totient is φ = 21915514782.

The previous prime is 21915514781. The next prime is 21915514811. The reversal of 21915514783 is 38741551912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21915514783 - 2¹ = 21915514781 is a prime.

Together with 21915514781, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21915514781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10957757391 + 10957757392.

It is an arithmetic number, because the mean of its divisors is an integer number (10957757392).

Almost surely, 2^21915514783 is an apocalyptic number.

21915514783 is a deficient number, since it is larger than the sum of its proper divisors (1).

21915514783 is an equidigital number, since it uses as much as digits as its factorization.

21915514783 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302400, while the sum is 46.

The spelling of 21915514783 in words is "twenty-one billion, nine hundred fifteen million, five hundred fourteen thousand, seven hundred eighty-three".