1661374266747 has 12 divisors (see below), whose sum is σ = 2398670539704. Its totient is φ = 1022384163840.

The previous prime is 1661374266611. The next prime is 1661374266757. The reversal of 1661374266747 is 7476624731661.

It is a happy number.

It is not a de Polignac number, because 1661374266747 - 2⁸ = 1661374266491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1661374266757) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1638435654 + ... + 1638436667.

It is an arithmetic number, because the mean of its divisors is an integer number (199889211642).

Almost surely, 2^{1661374266747} is an apocalyptic number.

1661374266747 is a deficient number, since it is larger than the sum of its proper divisors (737296272957).

1661374266747 is a wasteful number, since it uses less digits than its factorization.

1661374266747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3276872350 (or 3276872337 counting only the distinct ones).

The product of its digits is 42674688, while the sum is 60.

The spelling of 1661374266747 in words is "one trillion, six hundred sixty-one billion, three hundred seventy-four million, two hundred sixty-six thousand, seven hundred forty-seven".