21496971077 has 2 divisors, whose sum is σ = 21496971078. Its totient is φ = 21496971076.

The previous prime is 21496971059. The next prime is 21496971079. The reversal of 21496971077 is 77017969412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16119095521 + 5377875556 = 126961^2 + 73334^2 .

It is a cyclic number.

It is not a de Polignac number, because 21496971077 - 2¹⁴ = 21496954693 is a prime.

Together with 21496971079, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21496971079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10748485538 + 10748485539.

It is an arithmetic number, because the mean of its divisors is an integer number (10748485539).

Almost surely, 2^21496971077 is an apocalyptic number.

It is an amenable number.

21496971077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21496971077 is an equidigital number, since it uses as much as digits as its factorization.

21496971077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1333584, while the sum is 53.

The spelling of 21496971077 in words is "twenty-one billion, four hundred ninety-six million, nine hundred seventy-one thousand, seventy-seven".