21355466727461 has 2 divisors, whose sum is σ = 21355466727462. Its totient is φ = 21355466727460.

The previous prime is 21355466727457. The next prime is 21355466727563. The reversal of 21355466727461 is 16472766455312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21319136080225 + 36330647236 = 4617265^2 + 190606^2 .

It is a cyclic number.

It is not a de Polignac number, because 21355466727461 - 2² = 21355466727457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21355466727461.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21355466717461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10677733363730 + 10677733363731.

It is an arithmetic number, because the mean of its divisors is an integer number (10677733363731).

Almost surely, 2^{21355466727461} is an apocalyptic number.

It is an amenable number.

21355466727461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21355466727461 is an equidigital number, since it uses as much as digits as its factorization.

21355466727461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50803200, while the sum is 59.

The spelling of 21355466727461 in words is "twenty-one trillion, three hundred fifty-five billion, four hundred sixty-six million, seven hundred twenty-seven thousand, four hundred sixty-one".