21153891337 has 2 divisors, whose sum is σ = 21153891338. Its totient is φ = 21153891336.

The previous prime is 21153891313. The next prime is 21153891349. The reversal of 21153891337 is 73319835112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17210553721 + 3943337616 = 131189^2 + 62796^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21153891337 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21153891293 and 21153891302.

It is not a weakly prime, because it can be changed into another prime (21153891037) 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, 10576945668 + 10576945669.

It is an arithmetic number, because the mean of its divisors is an integer number (10576945669).

Almost surely, 2^21153891337 is an apocalyptic number.

It is an amenable number.

21153891337 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153891337 is an equidigital number, since it uses as much as digits as its factorization.

21153891337 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 43.

The spelling of 21153891337 in words is "twenty-one billion, one hundred fifty-three million, eight hundred ninety-one thousand, three hundred thirty-seven".