21598116 has 12 divisors (see below), whose sum is σ = 50395632. Its totient is φ = 7199368.

The previous prime is 21598111. The next prime is 21598123. The reversal of 21598116 is 61189512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21598116² = 932957229498912, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21598111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 899910 + ... + 899933.

It is an arithmetic number, because the mean of its divisors is an integer number (4199636).

Almost surely, 2^21598116 is an apocalyptic number.

It is an amenable number.

21598116 is an abundant number, since it is smaller than the sum of its proper divisors (28797516).

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

21598116 is a wasteful number, since it uses less digits than its factorization.

21598116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1799850 (or 1799848 counting only the distinct ones).

The product of its digits is 4320, while the sum is 33.

The square root of 21598116 is about 4647.3773249006. The cubic root of 21598116 is about 278.4872327875.

The spelling of 21598116 in words is "twenty-one million, five hundred ninety-eight thousand, one hundred sixteen".