640122163385 has 8 divisors (see below), whose sum is σ = 813331690056. Its totient is φ = 481974334720.

The previous prime is 640122163381. The next prime is 640122163391. The reversal of 640122163385 is 583361221046.

It can be written as a sum of positive squares in 4 ways, for example, as 354897807289 + 285224356096 = 595733^2 + 534064^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 640122163385 - 2² = 640122163381 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640122163381) 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, 3765424406 + ... + 3765424575.

It is an arithmetic number, because the mean of its divisors is an integer number (101666461257).

Almost surely, 2^640122163385 is an apocalyptic number.

It is an amenable number.

640122163385 is a deficient number, since it is larger than the sum of its proper divisors (173209526671).

640122163385 is a wasteful number, since it uses less digits than its factorization.

640122163385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7530849003.

The product of its (nonzero) digits is 207360, while the sum is 41.

The spelling of 640122163385 in words is "six hundred forty billion, one hundred twenty-two million, one hundred sixty-three thousand, three hundred eighty-five".