21075798 has 8 divisors (see below), whose sum is σ = 42151608. Its totient is φ = 7025264.

The previous prime is 21075781. The next prime is 21075809. The reversal of 21075798 is 89757012.

It is a sphenic number, since it is the product of 3 distinct primes.

21075798 is an admirable number.

It is a super-2 number, since 2×21075798² = 888378522673608, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1756311 + ... + 1756322.

It is an arithmetic number, because the mean of its divisors is an integer number (5268951).

Almost surely, 2^21075798 is an apocalyptic number.

21075798 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21075798 is a wasteful number, since it uses less digits than its factorization.

21075798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3512638.

The product of its (nonzero) digits is 35280, while the sum is 39.

The square root of 21075798 is about 4590.8384855057. The cubic root of 21075798 is about 276.2239570598.

The spelling of 21075798 in words is "twenty-one million, seventy-five thousand, seven hundred ninety-eight".