21213415166357 has 4 divisors (see below), whose sum is σ = 21215967625056. Its totient is φ = 21210862707660.

The previous prime is 21213415166347. The next prime is 21213415166399. The reversal of 21213415166357 is 75366151431212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21213415166357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213415166347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1276216883 + ... + 1276233504.

It is an arithmetic number, because the mean of its divisors is an integer number (5303991906264).

Almost surely, 2^{21213415166357} is an apocalyptic number.

It is an amenable number.

21213415166357 is a deficient number, since it is larger than the sum of its proper divisors (2552458699).

21213415166357 is an equidigital number, since it uses as much as digits as its factorization.

21213415166357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2552458698.

The product of its digits is 907200, while the sum is 47.

Adding to 21213415166357 its reverse (75366151431212), we get a palindrome (96579566597569).

The spelling of 21213415166357 in words is "twenty-one trillion, two hundred thirteen billion, four hundred fifteen million, one hundred sixty-six thousand, three hundred fifty-seven".