21490200 has 72 divisors (see below), whose sum is σ = 72177300. Its totient is φ = 5730240.

The previous prime is 21490199. The next prime is 21490213. The reversal of 21490200 is 209412.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 4170 + ... + 7769.

Almost surely, 2^21490200 is an apocalyptic number.

21490200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21490200 is an abundant number, since it is smaller than the sum of its proper divisors (50687100).

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

21490200 is a wasteful number, since it uses less digits than its factorization.

21490200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11961 (or 11949 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21490200 is about 4635.7523661214. The cubic root of 21490200 is about 278.0226332866.

Adding to 21490200 its reverse (209412), we get a palindrome (21699612).

The spelling of 21490200 in words is "twenty-one million, four hundred ninety thousand, two hundred".