21259798 has 16 divisors (see below), whose sum is σ = 36529920. Its totient is φ = 9090216.

The previous prime is 21259789. The next prime is 21259801. The reversal of 21259798 is 89795212.

It is a super-2 number, since 2×21259798² = 903958022001608, which contains 22 as substring.

It is a congruent number.

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, 5533 + ... + 8551.

It is an arithmetic number, because the mean of its divisors is an integer number (2283120).

Almost surely, 2^21259798 is an apocalyptic number.

21259798 is a deficient number, since it is larger than the sum of its proper divisors (15270122).

21259798 is a wasteful number, since it uses less digits than its factorization.

21259798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3531.

The product of its digits is 90720, while the sum is 43.

The square root of 21259798 is about 4610.8348484846. The cubic root of 21259798 is about 277.0254769409.

The spelling of 21259798 in words is "twenty-one million, two hundred fifty-nine thousand, seven hundred ninety-eight".