1661366590 has 64 divisors (see below), whose sum is σ = 3369776256. Its totient is φ = 585142272.

The previous prime is 1661366557. The next prime is 1661366591. The reversal of 1661366590 is 956631661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661366591) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1772602 + ... + 1773538.

It is an arithmetic number, because the mean of its divisors is an integer number (52652754).

Almost surely, 2^1661366590 is an apocalyptic number.

1661366590 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1661366590 is an abundant number, since it is smaller than the sum of its proper divisors (1708409666).

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

1661366590 is a wasteful number, since it uses less digits than its factorization.

1661366590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1573.

The product of its (nonzero) digits is 174960, while the sum is 43.

The square root of 1661366590 is about 40759.8649408950. The cubic root of 1661366590 is about 1184.3729797772.

The spelling of 1661366590 in words is "one billion, six hundred sixty-one million, three hundred sixty-six thousand, five hundred ninety".