1661255623199 has 8 divisors (see below), whose sum is σ = 1708919689488. Its totient is φ = 1613737097280.

The previous prime is 1661255623127. The next prime is 1661255623241. The reversal of 1661255623199 is 9913265521661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1661255623199 - 2²⁴ = 1661238845983 is a prime.

It is a super-2 number, since 2×1661255623199² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661255629199) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36361937 + ... + 36407594.

It is an arithmetic number, because the mean of its divisors is an integer number (213614961186).

Almost surely, 2^{1661255623199} is an apocalyptic number.

1661255623199 is a deficient number, since it is larger than the sum of its proper divisors (47664066289).

1661255623199 is an equidigital number, since it uses as much as digits as its factorization.

1661255623199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72770185.

The product of its digits is 5248800, while the sum is 56.

The spelling of 1661255623199 in words is "one trillion, six hundred sixty-one billion, two hundred fifty-five million, six hundred twenty-three thousand, one hundred ninety-nine".