40001998 has 8 divisors (see below), whose sum is σ = 60030000. Its totient is φ = 19992000.

The previous prime is 40001987. The next prime is 40001999. The reversal of 40001998 is 89910004.

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

40001998 is a modest number, since divided by 1998 gives 40 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40001999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5503 + ... + 10501.

It is an arithmetic number, because the mean of its divisors is an integer number (7503750).

Almost surely, 2^40001998 is an apocalyptic number.

40001998 is a deficient number, since it is larger than the sum of its proper divisors (20028002).

40001998 is a wasteful number, since it uses less digits than its factorization.

40001998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9002.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 40001998 is about 6324.7132741335. The cubic root of 40001998 is about 342.0008834604. Note that the first 3 decimals are identical.

The spelling of 40001998 in words is "forty million, one thousand, nine hundred ninety-eight".