1640342886 has 128 divisors (see below), whose sum is σ = 4331335680. Its totient is φ = 401836032.

The previous prime is 1640342881. The next prime is 1640342909. The reversal of 1640342886 is 6882430461.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640342881) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 732160 + ... + 734396.

It is an arithmetic number, because the mean of its divisors is an integer number (33838560).

Almost surely, 2^1640342886 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640342886, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2165667840).

1640342886 is an abundant number, since it is smaller than the sum of its proper divisors (2690992794).

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

1640342886 is a wasteful number, since it uses less digits than its factorization.

1640342886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2358.

The product of its (nonzero) digits is 221184, while the sum is 42.

The square root of 1640342886 is about 40501.1467245065. The cubic root of 1640342886 is about 1179.3558885362.

The spelling of 1640342886 in words is "one billion, six hundred forty million, three hundred forty-two thousand, eight hundred eighty-six".