1405640666251 has 2 divisors, whose sum is σ = 1405640666252. Its totient is φ = 1405640666250.

The previous prime is 1405640666197. The next prime is 1405640666263. The reversal of 1405640666251 is 1526660465041.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1405640666251 - 2⁹ = 1405640665739 is a prime.

It is not a weakly prime, because it can be changed into another prime (1405640666051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 702820333125 + 702820333126.

It is an arithmetic number, because the mean of its divisors is an integer number (702820333126).

Almost surely, 2^{1405640666251} is an apocalyptic number.

1405640666251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1405640666251 is an equidigital number, since it uses as much as digits as its factorization.

1405640666251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1036800, while the sum is 46.

The spelling of 1405640666251 in words is "one trillion, four hundred five billion, six hundred forty million, six hundred sixty-six thousand, two hundred fifty-one".