1661610111644 has 24 divisors (see below), whose sum is σ = 3339919833600. Its totient is φ = 708540131376.

The previous prime is 1661610111589. The next prime is 1661610111713. The reversal of 1661610111644 is 4461110161661.

It is a super-2 number, since 2×1661610111644² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1661610111598 and 1661610111607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 149097992 + ... + 149109135.

It is an arithmetic number, because the mean of its divisors is an integer number (139163326400).

Almost surely, 2^{1661610111644} is an apocalyptic number.

1661610111644 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1661610111644 is an abundant number, since it is smaller than the sum of its proper divisors (1678309721956).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661610111644 is a wasteful number, since it uses less digits than its factorization.

1661610111644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298207337 (or 298207335 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 1661610111644 in words is "one trillion, six hundred sixty-one billion, six hundred ten million, one hundred eleven thousand, six hundred forty-four".