21892697549 has 2 divisors, whose sum is σ = 21892697550. Its totient is φ = 21892697548.

The previous prime is 21892697521. The next prime is 21892697557. The reversal of 21892697549 is 94579629812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13872599524 + 8020098025 = 117782^2 + 89555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21892697549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21892697491 and 21892697500.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21892697509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10946348774 + 10946348775.

It is an arithmetic number, because the mean of its divisors is an integer number (10946348775).

Almost surely, 2^21892697549 is an apocalyptic number.

It is an amenable number.

21892697549 is a deficient number, since it is larger than the sum of its proper divisors (1).

21892697549 is an equidigital number, since it uses as much as digits as its factorization.

21892697549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19595520, while the sum is 62.

The spelling of 21892697549 in words is "twenty-one billion, eight hundred ninety-two million, six hundred ninety-seven thousand, five hundred forty-nine".