19840090 has 16 divisors (see below), whose sum is σ = 35942472. Its totient is φ = 7884864.

The previous prime is 19840049. The next prime is 19840091. The reversal of 19840090 is 9004891.

It can be written as a sum of positive squares in 4 ways, for example, as 9529569 + 10310521 = 3087^2 + 3211^2 .

It is not an unprimeable number, because it can be changed into a prime (19840091) 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, 4749 + ... + 7888.

Almost surely, 2^19840090 is an apocalyptic number.

19840090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19840090 is a deficient number, since it is larger than the sum of its proper divisors (16102382).

19840090 is a wasteful number, since it uses less digits than its factorization.

19840090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12801.

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

The square root of 19840090 is about 4454.2215930508. The cubic root of 19840090 is about 270.7163874324.

The spelling of 19840090 in words is "nineteen million, eight hundred forty thousand, ninety".