21246005245 has 4 divisors (see below), whose sum is σ = 25495206300. Its totient is φ = 16996804192.

The previous prime is 21246005239. The next prime is 21246005269. The reversal of 21246005245 is 54250064212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7366102276 + 13879902969 = 85826^2 + 117813^2 .

It is a cyclic number.

It is not a de Polignac number, because 21246005245 - 2⁵ = 21246005213 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2124600520 + ... + 2124600529.

It is an arithmetic number, because the mean of its divisors is an integer number (6373801575).

Almost surely, 2^21246005245 is an apocalyptic number.

It is an amenable number.

21246005245 is a deficient number, since it is larger than the sum of its proper divisors (4249201055).

21246005245 is an equidigital number, since it uses as much as digits as its factorization.

21246005245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4249201054.

The product of its (nonzero) digits is 19200, while the sum is 31.

Adding to 21246005245 its reverse (54250064212), we get a palindrome (75496069457).

The spelling of 21246005245 in words is "twenty-one billion, two hundred forty-six million, five thousand, two hundred forty-five".