21997902413677 has 2 divisors, whose sum is σ = 21997902413678. Its totient is φ = 21997902413676.

The previous prime is 21997902413611. The next prime is 21997902413681. The reversal of 21997902413677 is 77631420979912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15165502392681 + 6832400020996 = 3894291^2 + 2613886^2 .

It is a cyclic number.

It is not a de Polignac number, because 21997902413677 - 2⁴³ = 13201809391469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21997902413687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10998951206838 + 10998951206839.

It is an arithmetic number, because the mean of its divisors is an integer number (10998951206839).

Almost surely, 2^{21997902413677} is an apocalyptic number.

It is an amenable number.

21997902413677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21997902413677 is an equidigital number, since it uses as much as digits as its factorization.

21997902413677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72013536, while the sum is 67.

The spelling of 21997902413677 in words is "twenty-one trillion, nine hundred ninety-seven billion, nine hundred two million, four hundred thirteen thousand, six hundred seventy-seven".