646738140 has 96 divisors (see below), whose sum is σ = 1922647104. Its totient is φ = 161873920.

The previous prime is 646738129. The next prime is 646738177. The reversal of 646738140 is 41837646.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 530812 + ... + 532028.

It is an arithmetic number, because the mean of its divisors is an integer number (20027574).

Almost surely, 2^646738140 is an apocalyptic number.

646738140 is a gapful number since it is divisible by the number (60) 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 646738140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (961323552).

646738140 is an abundant number, since it is smaller than the sum of its proper divisors (1275908964).

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

646738140 is a wasteful number, since it uses less digits than its factorization.

646738140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767 (or 1765 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 39.

The square root of 646738140 is about 25431.0467735797. The cubic root of 646738140 is about 864.7876743944.

The spelling of 646738140 in words is "six hundred forty-six million, seven hundred thirty-eight thousand, one hundred forty".