1631665266 has 64 divisors (see below), whose sum is σ = 4100751360. Its totient is φ = 420456960.

The previous prime is 1631665249. The next prime is 1631665279. The reversal of 1631665266 is 6625661361.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44770 + ... + 72578.

It is an arithmetic number, because the mean of its divisors is an integer number (64074240).

Almost surely, 2^1631665266 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1631665266, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2050375680).

1631665266 is an abundant number, since it is smaller than the sum of its proper divisors (2469086094).

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

1631665266 is a wasteful number, since it uses less digits than its factorization.

1631665266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27959.

The product of its digits is 233280, while the sum is 42.

The square root of 1631665266 is about 40393.8765903942. The cubic root of 1631665266 is about 1177.2725635712.

The spelling of 1631665266 in words is "one billion, six hundred thirty-one million, six hundred sixty-five thousand, two hundred sixty-six".