1661255622407 has 2 divisors, whose sum is σ = 1661255622408. Its totient is φ = 1661255622406.

The previous prime is 1661255622401. The next prime is 1661255622419. The reversal of 1661255622407 is 7042265521661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1661255622407 - 2²⁰ = 1661254573831 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1661255622401) 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 as a sum of consecutive naturals, namely, 830627811203 + 830627811204.

It is an arithmetic number, because the mean of its divisors is an integer number (830627811204).

Almost surely, 2^{1661255622407} is an apocalyptic number.

1661255622407 is a deficient number, since it is larger than the sum of its proper divisors (1).

1661255622407 is an equidigital number, since it uses as much as digits as its factorization.

1661255622407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1209600, while the sum is 47.

The spelling of 1661255622407 in words is "one trillion, six hundred sixty-one billion, two hundred fifty-five million, six hundred twenty-two thousand, four hundred seven".