21998260 has 24 divisors (see below), whose sum is σ = 46349856. Its totient is φ = 8770080.

The previous prime is 21998243. The next prime is 21998267. The reversal of 21998260 is 6289912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21998267) 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, 4959 + ... + 8281.

It is an arithmetic number, because the mean of its divisors is an integer number (1931244).

Almost surely, 2^21998260 is an apocalyptic number.

21998260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21998260 is an abundant number, since it is smaller than the sum of its proper divisors (24351596).

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

21998260 is a wasteful number, since it uses less digits than its factorization.

21998260 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663 (or 3661 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 21998260 is about 4690.2302715325. The cubic root of 21998260 is about 280.1965456762.

The spelling of 21998260 in words is "twenty-one million, nine hundred ninety-eight thousand, two hundred sixty".