21145451357 has 2 divisors, whose sum is σ = 21145451358. Its totient is φ = 21145451356.

The previous prime is 21145451347. The next prime is 21145451381. The reversal of 21145451357 is 75315454112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21145231396 + 219961 = 145414^2 + 469^2 .

It is a cyclic number.

It is not a de Polignac number, because 21145451357 - 2³⁰ = 20071709533 is a prime.

It is a super-2 number, since 2×21145451357² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21145451357.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145451347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572725678 + 10572725679.

It is an arithmetic number, because the mean of its divisors is an integer number (10572725679).

Almost surely, 2^21145451357 is an apocalyptic number.

It is an amenable number.

21145451357 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145451357 is an equidigital number, since it uses as much as digits as its factorization.

21145451357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 84000, while the sum is 38.

The spelling of 21145451357 in words is "twenty-one billion, one hundred forty-five million, four hundred fifty-one thousand, three hundred fifty-seven".