28219994 has 16 divisors (see below), whose sum is σ = 46460736. Its totient is φ = 12748800.

The previous prime is 28219973. The next prime is 28219999. The reversal of 28219994 is 49991282.

It is a super-2 number, since 2×28219994² = 1592736122720072, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28219999) 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, 167 + ... + 7514.

It is an arithmetic number, because the mean of its divisors is an integer number (2903796).

Almost surely, 2^28219994 is an apocalyptic number.

28219994 is a deficient number, since it is larger than the sum of its proper divisors (18240742).

28219994 is a wasteful number, since it uses less digits than its factorization.

28219994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7861.

The product of its digits is 93312, while the sum is 44.

The square root of 28219994 is about 5312.2494293849. The cubic root of 28219994 is about 304.4520988460.

It can be divided in two parts, 28 and 219994, that added together give a palindrome (220022).

The spelling of 28219994 in words is "twenty-eight million, two hundred nineteen thousand, nine hundred ninety-four".