1661666104 has 32 divisors (see below), whose sum is σ = 3563233920. Its totient is φ = 711638496.

The previous prime is 1661666101. The next prime is 1661666113. The reversal of 1661666104 is 4016661661.

It is a super-2 number, since 2×1661666104² = 5522268482365077632, which contains 22 as substring.

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, 75547 + ... + 95029.

It is an arithmetic number, because the mean of its divisors is an integer number (111351060).

Almost surely, 2^1661666104 is an apocalyptic number.

1661666104 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

1661666104 is an abundant number, since it is smaller than the sum of its proper divisors (1901567816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661666104 is a wasteful number, since it uses less digits than its factorization.

1661666104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21019 (or 21015 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 1661666104 is about 40763.5389042708. The cubic root of 1661666104 is about 1184.4441490935. Note that the first 3 decimals are identical.

The spelling of 1661666104 in words is "one billion, six hundred sixty-one million, six hundred sixty-six thousand, one hundred four".