1661666103 has 8 divisors (see below), whose sum is σ = 2461727600. Its totient is φ = 1107777384.

The previous prime is 1661666101. The next prime is 1661666113. The reversal of 1661666103 is 3016661661.

It is a happy number.

It is not a de Polignac number, because 1661666103 - 2¹ = 1661666101 is a prime.

It is a super-2 number, since 2×1661666103² = 5522268475718413218, 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 (1661666101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30771568 + ... + 30771621.

It is an arithmetic number, because the mean of its divisors is an integer number (307715950).

Almost surely, 2^1661666103 is an apocalyptic number.

1661666103 is a deficient number, since it is larger than the sum of its proper divisors (800061497).

1661666103 is an equidigital number, since it uses as much as digits as its factorization.

1661666103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61543198 (or 61543192 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 1661666103 is about 40763.5388920049. The cubic root of 1661666103 is about 1184.4441488559. Note that the first 3 decimals are identical.

The spelling of 1661666103 in words is "one billion, six hundred sixty-one million, six hundred sixty-six thousand, one hundred three".