1661722903 has 4 divisors (see below), whose sum is σ = 1664178120. Its totient is φ = 1659267688.

The previous prime is 1661722901. The next prime is 1661722913. The reversal of 1661722903 is 3092271661.

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

It is a cyclic number.

It is not a de Polignac number, because 1661722903 - 2¹ = 1661722901 is a prime.

It is a super-2 number, since 2×1661722903² = 5522646012709494818, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661722901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1226593 + ... + 1227946.

It is an arithmetic number, because the mean of its divisors is an integer number (416044530).

Almost surely, 2^1661722903 is an apocalyptic number.

1661722903 is a deficient number, since it is larger than the sum of its proper divisors (2455217).

1661722903 is an equidigital number, since it uses as much as digits as its factorization.

1661722903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2455216.

The product of its (nonzero) digits is 27216, while the sum is 37.

The square root of 1661722903 is about 40764.2355870928. The cubic root of 1661722903 is about 1184.4576444796.

The spelling of 1661722903 in words is "one billion, six hundred sixty-one million, seven hundred twenty-two thousand, nine hundred three".