1986804990 has 64 divisors (see below), whose sum is σ = 5307508800. Its totient is φ = 528878592.

The previous prime is 1986804983. The next prime is 1986804991. The reversal of 1986804990 is 994086891.

1986804990 is a `hidden beast` number, since 1 + 98 + 68 + 0 + 499 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1986804991) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153906 + ... + 166314.

It is an arithmetic number, because the mean of its divisors is an integer number (82929825).

Almost surely, 2^1986804990 is an apocalyptic number.

1986804990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1986804990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2653754400).

1986804990 is an abundant number, since it is smaller than the sum of its proper divisors (3320703810).

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

1986804990 is a wasteful number, since it uses less digits than its factorization.

1986804990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13018 (or 13012 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 54.

The square root of 1986804990 is about 44573.5907236561. The cubic root of 1986804990 is about 1257.1441555784.

The spelling of 1986804990 in words is "one billion, nine hundred eighty-six million, eight hundred four thousand, nine hundred ninety".