21357177253 has 2 divisors, whose sum is σ = 21357177254. Its totient is φ = 21357177252.

The previous prime is 21357177251. The next prime is 21357177341. The reversal of 21357177253 is 35277175312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13297087969 + 8060089284 = 115313^2 + 89778^2 .

It is a cyclic number.

It is not a de Polignac number, because 21357177253 - 2¹ = 21357177251 is a prime.

It is a super-2 number, since 2×21357177253² (a number of 21 digits) contains 22 as substring.

Together with 21357177251, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21357177251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678588626 + 10678588627.

It is an arithmetic number, because the mean of its divisors is an integer number (10678588627).

Almost surely, 2^21357177253 is an apocalyptic number.

It is an amenable number.

21357177253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21357177253 is an equidigital number, since it uses as much as digits as its factorization.

21357177253 is an evil number, because the sum of its binary digits is even.

The product of its digits is 308700, while the sum is 43.

The spelling of 21357177253 in words is "twenty-one billion, three hundred fifty-seven million, one hundred seventy-seven thousand, two hundred fifty-three".