1661332421045 has 32 divisors (see below), whose sum is σ = 2177071223040. Its totient is φ = 1207000304640.

The previous prime is 1661332421041. The next prime is 1661332421059. The reversal of 1661332421045 is 5401242331661.

It is not a de Polignac number, because 1661332421045 - 2² = 1661332421041 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661332421041) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 349090376 + ... + 349095134.

It is an arithmetic number, because the mean of its divisors is an integer number (68033475720).

Almost surely, 2^{1661332421045} is an apocalyptic number.

It is an amenable number.

1661332421045 is a deficient number, since it is larger than the sum of its proper divisors (515738801995).

1661332421045 is a wasteful number, since it uses less digits than its factorization.

1661332421045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9965.

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 1661332421045 in words is "one trillion, six hundred sixty-one billion, three hundred thirty-two million, four hundred twenty-one thousand, forty-five".