664151838 has 32 divisors (see below), whose sum is σ = 1540725504. Its totient is φ = 186924672.

The previous prime is 664151837. The next prime is 664151857. The reversal of 664151838 is 838151466.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 664151838.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664151837) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 115195 + ... + 120822.

It is an arithmetic number, because the mean of its divisors is an integer number (48147672).

Almost surely, 2^664151838 is an apocalyptic number.

664151838 is an abundant number, since it is smaller than the sum of its proper divisors (876573666).

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

664151838 is a wasteful number, since it uses less digits than its factorization.

664151838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236096.

The product of its digits is 138240, while the sum is 42.

The square root of 664151838 is about 25771.1435136278. The cubic root of 664151838 is about 872.4806280267.

The spelling of 664151838 in words is "six hundred sixty-four million, one hundred fifty-one thousand, eight hundred thirty-eight".