1661500606 has 4 divisors (see below), whose sum is σ = 2492250912. Its totient is φ = 830750302.

The previous prime is 1661500591. The next prime is 1661500609. The reversal of 1661500606 is 6060051661.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661500609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 415375150 + ... + 415375153.

It is an arithmetic number, because the mean of its divisors is an integer number (623062728).

Almost surely, 2^1661500606 is an apocalyptic number.

1661500606 is a deficient number, since it is larger than the sum of its proper divisors (830750306).

1661500606 is an equidigital number, since it uses as much as digits as its factorization.

1661500606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830750305.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 1661500606 is about 40761.5088778617. The cubic root of 1661500606 is about 1184.4048251793.

The spelling of 1661500606 in words is "one billion, six hundred sixty-one million, five hundred thousand, six hundred six".