1664127740 has 144 divisors (see below), whose sum is σ = 4146702336. Its totient is φ = 554716800.

The previous prime is 1664127719. The next prime is 1664127757. The reversal of 1664127740 is 477214661.

It is a happy number.

It is a super-2 number, since 2×1664127740² = 5538642270075015200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1664127694 and 1664127703.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16156529 + ... + 16156631.

It is an arithmetic number, because the mean of its divisors is an integer number (28796544).

Almost surely, 2^1664127740 is an apocalyptic number.

1664127740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1664127740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2073351168).

1664127740 is an abundant number, since it is smaller than the sum of its proper divisors (2482574596).

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

1664127740 is a wasteful number, since it uses less digits than its factorization.

1664127740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280 (or 175 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 1664127740 is about 40793.7218208881. The cubic root of 1664127740 is about 1185.0287494434.

The spelling of 1664127740 in words is "one billion, six hundred sixty-four million, one hundred twenty-seven thousand, seven hundred forty".