21953963461 has 2 divisors, whose sum is σ = 21953963462. Its totient is φ = 21953963460.

The previous prime is 21953963441. The next prime is 21953963491. The reversal of 21953963461 is 16436935912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18903500100 + 3050463361 = 137490^2 + 55231^2 .

It is a cyclic number.

It is not a de Polignac number, because 21953963461 - 2¹⁵ = 21953930693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21953963401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10976981730 + 10976981731.

It is an arithmetic number, because the mean of its divisors is an integer number (10976981731).

Almost surely, 2^21953963461 is an apocalyptic number.

It is an amenable number.

21953963461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21953963461 is an equidigital number, since it uses as much as digits as its factorization.

21953963461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1049760, while the sum is 49.

The spelling of 21953963461 in words is "twenty-one billion, nine hundred fifty-three million, nine hundred sixty-three thousand, four hundred sixty-one".