1661202506 has 8 divisors (see below), whose sum is σ = 2501067780. Its totient is φ = 827513248.

The previous prime is 1661202467. The next prime is 1661202551. The reversal of 1661202506 is 6052021661.

It can be written as a sum of positive squares in 2 ways, for example, as 1365672025 + 295530481 = 36955^2 + 17191^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1543331 + ... + 1544406.

Almost surely, 2^1661202506 is an apocalyptic number.

1661202506 is a deficient number, since it is larger than the sum of its proper divisors (839865274).

1661202506 is a wasteful number, since it uses less digits than its factorization.

1661202506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3088008.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1661202506 is about 40757.8520778512. The cubic root of 1661202506 is about 1184.3339871680. Note that the first 3 decimals are identical.

The spelling of 1661202506 in words is "one billion, six hundred sixty-one million, two hundred two thousand, five hundred six".