1640406878938 has 8 divisors (see below), whose sum is σ = 2460619742688. Its totient is φ = 820200298044.

The previous prime is 1640406878927. The next prime is 1640406878953. The reversal of 1640406878938 is 8398786040461.

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

It is a super-2 number, since 2×1640406878938² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1640406878938.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 852256 + ... + 2001787.

It is an arithmetic number, because the mean of its divisors is an integer number (307577467836).

Almost surely, 2^{1640406878938} is an apocalyptic number.

1640406878938 is a deficient number, since it is larger than the sum of its proper divisors (820212863750).

1640406878938 is a wasteful number, since it uses less digits than its factorization.

1640406878938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3141428.

The product of its (nonzero) digits is 55738368, while the sum is 64.

The spelling of 1640406878938 in words is "one trillion, six hundred forty billion, four hundred six million, eight hundred seventy-eight thousand, nine hundred thirty-eight".