19389890 has 16 divisors (see below), whose sum is σ = 37586808. Its totient is φ = 7159296.

The previous prime is 19389889. The next prime is 19389907. The reversal of 19389890 is 9898391.

It can be written as a sum of positive squares in 4 ways, for example, as 7230721 + 12159169 = 2689^2 + 3487^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74447 + ... + 74706.

Almost surely, 2^19389890 is an apocalyptic number.

19389890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19389890 is a deficient number, since it is larger than the sum of its proper divisors (18196918).

19389890 is a wasteful number, since it uses less digits than its factorization.

19389890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149173.

The product of its (nonzero) digits is 139968, while the sum is 47.

The square root of 19389890 is about 4403.3952809168. The cubic root of 19389890 is about 268.6530539097.

The spelling of 19389890 in words is "nineteen million, three hundred eighty-nine thousand, eight hundred ninety".