640378719 has 12 divisors (see below), whose sum is σ = 965208816. Its totient is φ = 408357312.

The previous prime is 640378657. The next prime is 640378727. The reversal of 640378719 is 917873046.

It is not a de Polignac number, because 640378719 - 2⁷ = 640378591 is a prime.

It is a super-2 number, since 2×640378719² = 820169807496161922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640378759) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1546602 + ... + 1547015.

It is an arithmetic number, because the mean of its divisors is an integer number (80434068).

Almost surely, 2^640378719 is an apocalyptic number.

640378719 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

640378719 is a deficient number, since it is larger than the sum of its proper divisors (324830097).

640378719 is a wasteful number, since it uses less digits than its factorization.

640378719 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3093646 (or 3093643 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 640378719 is about 25305.7052658091. The cubic root of 640378719 is about 861.9438269426.

The spelling of 640378719 in words is "six hundred forty million, three hundred seventy-eight thousand, seven hundred nineteen".