990401838 has 16 divisors (see below), whose sum is σ = 1984074240. Its totient is φ = 329588856.

The previous prime is 990401837. The next prime is 990401851. The reversal of 990401838 is 838104099.

It is a self number, because there is not a number n which added to its sum of digits gives 990401838.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (990401833) 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, 132328 + ... + 139611.

It is an arithmetic number, because the mean of its divisors is an integer number (124004640).

Almost surely, 2^990401838 is an apocalyptic number.

990401838 is an abundant number, since it is smaller than the sum of its proper divisors (993672402).

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

990401838 is a wasteful number, since it uses less digits than its factorization.

990401838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272551.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 990401838 is about 31470.6504222585. The cubic root of 990401838 is about 996.7903216537.

The spelling of 990401838 in words is "nine hundred ninety million, four hundred one thousand, eight hundred thirty-eight".