640037970 has 256 divisors, whose sum is σ = 2036482560. Its totient is φ = 142179840.
The previous prime is 640037927. The next prime is 640038001. The reversal of 640037970 is 79730046.
640037970 is a `hidden beast` number, since 640 + 0 + 3 + 7 + 9 + 7 + 0 = 666.
It is a Curzon number.
It is an unprimeable number.
It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 4671742 + ... + 4671878.
It is an arithmetic number, because the mean of its divisors is an integer number (7955010).
Almost surely, 2640037970 is an apocalyptic number.
It is a practical number, because each smaller number is the sum of distinct divisors of 640037970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1018241280).
640037970 is an abundant number, since it is smaller than the sum of its proper divisors (1396444590).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
640037970 is a wasteful number, since it uses less digits than its factorization.
640037970 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 199 (or 171 counting only the distinct ones).
The product of its (nonzero) digits is 31752, while the sum is 36.
The square root of 640037970 is about 25298.9717182339. The cubic root of 640037970 is about 861.7909181518.
The spelling of 640037970 in words is "six hundred forty million, thirty-seven thousand, nine hundred seventy".
• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.063 sec. • engine limits •