21225752461 has 2 divisors, whose sum is σ = 21225752462. Its totient is φ = 21225752460.

The previous prime is 21225752459. The next prime is 21225752479. The reversal of 21225752461 is 16425752212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21121099561 + 104652900 = 145331^2 + 10230^2 .

It is a cyclic number.

It is not a de Polignac number, because 21225752461 - 2¹ = 21225752459 is a prime.

Together with 21225752459, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21225752461.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21225752411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612876230 + 10612876231.

It is an arithmetic number, because the mean of its divisors is an integer number (10612876231).

Almost surely, 2^21225752461 is an apocalyptic number.

It is an amenable number.

21225752461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225752461 is an equidigital number, since it uses as much as digits as its factorization.

21225752461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 67200, while the sum is 37.

The spelling of 21225752461 in words is "twenty-one billion, two hundred twenty-five million, seven hundred fifty-two thousand, four hundred sixty-one".