640894146 has 16 divisors (see below), whose sum is σ = 1282099104. Its totient is φ = 213579584.

The previous prime is 640894141. The next prime is 640894153. The reversal of 640894146 is 641498046.

It is a junction number, because it is equal to n+sod(n) for n = 640894098 and 640894107.

It is not an unprimeable number, because it can be changed into a prime (640894141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20506 + ... + 41258.

It is an arithmetic number, because the mean of its divisors is an integer number (80131194).

Almost surely, 2^640894146 is an apocalyptic number.

640894146 is an abundant number, since it is smaller than the sum of its proper divisors (641204958).

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

640894146 is a wasteful number, since it uses less digits than its factorization.

640894146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25905.

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 640894146 is about 25315.8872252189. The cubic root of 640894146 is about 862.1750182501.

The spelling of 640894146 in words is "six hundred forty million, eight hundred ninety-four thousand, one hundred forty-six".