19684890 has 32 divisors (see below), whose sum is σ = 52493760. Its totient is φ = 5249232.

The previous prime is 19684877. The next prime is 19684909. The reversal of 19684890 is 9848691.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36184 + ... + 36723.

It is an arithmetic number, because the mean of its divisors is an integer number (1640430).

Almost surely, 2^19684890 is an apocalyptic number.

19684890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19684890 is an abundant number, since it is smaller than the sum of its proper divisors (32808870).

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

19684890 is a wasteful number, since it uses less digits than its factorization.

19684890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72923 (or 72917 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 19684890 is about 4436.7657138957. The cubic root of 19684890 is about 270.0086416987.

The spelling of 19684890 in words is "nineteen million, six hundred eighty-four thousand, eight hundred ninety".