1640690370 has 256 divisors, whose sum is σ = 5063731200. Its totient is φ = 374250240.

The previous prime is 1640690369. The next prime is 1640690377. The reversal of 1640690370 is 730960461.

1640690370 is a `hidden beast` number, since 1 + 640 + 6 + 9 + 0 + 3 + 7 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (1640690377) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3703369 + ... + 3703811.

It is an arithmetic number, because the mean of its divisors is an integer number (19780200).

Almost surely, 2^1640690370 is an apocalyptic number.

1640690370 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1640690370, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2531865600).

1640690370 is an abundant number, since it is smaller than the sum of its proper divisors (3423040830).

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

1640690370 is a wasteful number, since it uses less digits than its factorization.

1640690370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 1640690370 is about 40505.4363018102. The cubic root of 1640690370 is about 1179.4391594123.

The spelling of 1640690370 in words is "one billion, six hundred forty million, six hundred ninety thousand, three hundred seventy".