1245400627661 has 2 divisors, whose sum is σ = 1245400627662. Its totient is φ = 1245400627660.

The previous prime is 1245400627657. The next prime is 1245400627663. The reversal of 1245400627661 is 1667260045421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1034553436900 + 210847190761 = 1017130^2 + 459181^2 .

It is a cyclic number.

It is not a de Polignac number, because 1245400627661 - 2² = 1245400627657 is a prime.

Together with 1245400627663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1245400627663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 622700313830 + 622700313831.

It is an arithmetic number, because the mean of its divisors is an integer number (622700313831).

Almost surely, 2^{1245400627661} is an apocalyptic number.

It is an amenable number.

1245400627661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1245400627661 is an equidigital number, since it uses as much as digits as its factorization.

1245400627661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 483840, while the sum is 44.

The spelling of 1245400627661 in words is "one trillion, two hundred forty-five billion, four hundred million, six hundred twenty-seven thousand, six hundred sixty-one".