21495450 has 48 divisors (see below), whose sum is σ = 54460800. Its totient is φ = 5608320.

The previous prime is 21495433. The next prime is 21495451. The reversal of 21495450 is 5459412.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (21495451) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5526 + ... + 8574.

It is an arithmetic number, because the mean of its divisors is an integer number (1134600).

Almost surely, 2^21495450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21495450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27230400).

21495450 is an abundant number, since it is smaller than the sum of its proper divisors (32965350).

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

21495450 is a wasteful number, since it uses less digits than its factorization.

21495450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3111 (or 3106 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 21495450 is about 4636.3185826688. The cubic root of 21495450 is about 278.0452715121.

It can be divided in two parts, 21495 and 450, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21495450 in words is "twenty-one million, four hundred ninety-five thousand, four hundred fifty".