1661498989375 has 20 divisors (see below), whose sum is σ = 2079630055360. Its totient is φ = 1327009104000.

The previous prime is 1661498989363. The next prime is 1661498989387. The reversal of 1661498989375 is 5739898941661.

It is an interprime number because it is at equal distance from previous prime (1661498989363) and next prime (1661498989387).

It is not a de Polignac number, because 1661498989375 - 2¹¹ = 1661498987327 is a prime.

It is a Smith number, since the sum of its digits (76) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1810410 + ... + 2569159.

It is an arithmetic number, because the mean of its divisors is an integer number (103981502768).

Almost surely, 2^{1661498989375} is an apocalyptic number.

1661498989375 is a deficient number, since it is larger than the sum of its proper divisors (418131065985).

1661498989375 is an frugal number, since it uses more digits than its factorization.

1661498989375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4380196 (or 4380181 counting only the distinct ones).

The product of its digits is 705438720, while the sum is 76.

The spelling of 1661498989375 in words is "one trillion, six hundred sixty-one billion, four hundred ninety-eight million, nine hundred eighty-nine thousand, three hundred seventy-five".