16400638 has 8 divisors (see below), whose sum is σ = 25065288. Its totient is φ = 8045544.

The previous prime is 16400621. The next prime is 16400641. The reversal of 16400638 is 83600461.

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

It is a congruent number.

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, 77256 + ... + 77467.

It is an arithmetic number, because the mean of its divisors is an integer number (3133161).

Almost surely, 2^16400638 is an apocalyptic number.

16400638 is a deficient number, since it is larger than the sum of its proper divisors (8664650).

16400638 is a wasteful number, since it uses less digits than its factorization.

16400638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154778.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 16400638 is about 4049.7701169326. The cubic root of 16400638 is about 254.0701131181.

The spelling of 16400638 in words is "sixteen million, four hundred thousand, six hundred thirty-eight".