21073998 has 32 divisors (see below), whose sum is σ = 46189440. Its totient is φ = 6356960.

The previous prime is 21073991. The next prime is 21074023. The reversal of 21073998 is 89937012.

It is a super-2 number, since 2×21073998² = 888226783408008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17161 + ... + 18347.

It is an arithmetic number, because the mean of its divisors is an integer number (1443420).

Almost surely, 2^21073998 is an apocalyptic number.

21073998 is an abundant number, since it is smaller than the sum of its proper divisors (25115442).

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

21073998 is a wasteful number, since it uses less digits than its factorization.

21073998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1472.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 21073998 is about 4590.6424387007. The cubic root of 21073998 is about 276.2160931064.

It can be divided in two parts, 2107 and 3998, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 21073998 in words is "twenty-one million, seventy-three thousand, nine hundred ninety-eight".