20219890 has 32 divisors (see below), whose sum is σ = 37920960. Its totient is φ = 7756224.

The previous prime is 20219887. The next prime is 20219891. The reversal of 20219890 is 9891202.

It is a super-2 number, since 2×20219890² = 817687903224200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20219891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24972 + ... + 25768.

It is an arithmetic number, because the mean of its divisors is an integer number (1185030).

Almost surely, 2^20219890 is an apocalyptic number.

20219890 is a deficient number, since it is larger than the sum of its proper divisors (17701070).

20219890 is a wasteful number, since it uses less digits than its factorization.

20219890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 906.

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

The square root of 20219890 is about 4496.6531998810. The cubic root of 20219890 is about 272.4329268469.

It can be divided in two parts, 2021 and 9890, that added together give a palindrome (11911).

The spelling of 20219890 in words is "twenty million, two hundred nineteen thousand, eight hundred ninety".