640011389 has 2 divisors, whose sum is σ = 640011390. Its totient is φ = 640011388.

The previous prime is 640011349. The next prime is 640011401. The reversal of 640011389 is 983110046.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 512660164 + 127351225 = 22642^2 + 11285^2 .

It is a cyclic number.

It is not a de Polignac number, because 640011389 - 2²⁰ = 638962813 is a prime.

It is a super-2 number, since 2×640011389² = 819229156099418642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (640011349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320005694 + 320005695.

It is an arithmetic number, because the mean of its divisors is an integer number (320005695).

Almost surely, 2^640011389 is an apocalyptic number.

It is an amenable number.

640011389 is a deficient number, since it is larger than the sum of its proper divisors (1).

640011389 is an equidigital number, since it uses as much as digits as its factorization.

640011389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 640011389 is about 25298.4463752223. The cubic root of 640011389 is about 861.7789878276.

The spelling of 640011389 in words is "six hundred forty million, eleven thousand, three hundred eighty-nine".