2102457279721 has 2 divisors, whose sum is σ = 2102457279722. Its totient is φ = 2102457279720.

The previous prime is 2102457279691. The next prime is 2102457279827. The reversal of 2102457279721 is 1279727542012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1831120469721 + 271336810000 = 1353189^2 + 520900^2 .

It is a cyclic number.

It is not a de Polignac number, because 2102457279721 - 2¹¹ = 2102457277673 is a prime.

It is a super-2 number, since 2×2102457279721² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2102457279121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1051228639860 + 1051228639861.

It is an arithmetic number, because the mean of its divisors is an integer number (1051228639861).

Almost surely, 2^{2102457279721} is an apocalyptic number.

It is an amenable number.

2102457279721 is a deficient number, since it is larger than the sum of its proper divisors (1).

2102457279721 is an equidigital number, since it uses as much as digits as its factorization.

2102457279721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 987840, while the sum is 49.

The spelling of 2102457279721 in words is "two trillion, one hundred two billion, four hundred fifty-seven million, two hundred seventy-nine thousand, seven hundred twenty-one".