21727377461 has 2 divisors, whose sum is σ = 21727377462. Its totient is φ = 21727377460.

The previous prime is 21727377457. The next prime is 21727377509. The reversal of 21727377461 is 16477372712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11945178436 + 9782199025 = 109294^2 + 98905^2 .

It is a cyclic number.

It is not a de Polignac number, because 21727377461 - 2² = 21727377457 is a prime.

It is a super-3 number, since 3×21727377461³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21727371461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10863688730 + 10863688731.

It is an arithmetic number, because the mean of its divisors is an integer number (10863688731).

Almost surely, 2^21727377461 is an apocalyptic number.

It is an amenable number.

21727377461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21727377461 is an equidigital number, since it uses as much as digits as its factorization.

21727377461 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 691488, while the sum is 47.

The spelling of 21727377461 in words is "twenty-one billion, seven hundred twenty-seven million, three hundred seventy-seven thousand, four hundred sixty-one".