1661942545 has 8 divisors (see below), whose sum is σ = 1994760000. Its totient is φ = 1329268080.

The previous prime is 1661942489. The next prime is 1661942551. The reversal of 1661942545 is 5452491661.

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

It is not a de Polignac number, because 1661942545 - 2¹³ = 1661934353 is a prime.

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, 8251 + ... + 58240.

It is an arithmetic number, because the mean of its divisors is an integer number (249345000).

Almost surely, 2^1661942545 is an apocalyptic number.

It is an amenable number.

1661942545 is a deficient number, since it is larger than the sum of its proper divisors (332817455).

1661942545 is an equidigital number, since it uses as much as digits as its factorization.

1661942545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71495.

The product of its digits is 259200, while the sum is 43.

The square root of 1661942545 is about 40766.9295508013. The cubic root of 1661942545 is about 1184.5098283072.

The spelling of 1661942545 in words is "one billion, six hundred sixty-one million, nine hundred forty-two thousand, five hundred forty-five".