21552303397 has 2 divisors, whose sum is σ = 21552303398. Its totient is φ = 21552303396.

The previous prime is 21552303373. The next prime is 21552303407. The reversal of 21552303397 is 79330325512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18210422916 + 3341880481 = 134946^2 + 57809^2 .

It is a cyclic number.

It is not a de Polignac number, because 21552303397 - 2²⁷ = 21418085669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21552306397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10776151698 + 10776151699.

It is an arithmetic number, because the mean of its divisors is an integer number (10776151699).

Almost surely, 2^21552303397 is an apocalyptic number.

It is an amenable number.

21552303397 is a deficient number, since it is larger than the sum of its proper divisors (1).

21552303397 is an equidigital number, since it uses as much as digits as its factorization.

21552303397 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 170100, while the sum is 40.

The spelling of 21552303397 in words is "twenty-one billion, five hundred fifty-two million, three hundred three thousand, three hundred ninety-seven".