21489650 has 48 divisors (see below), whose sum is σ = 49205184. Its totient is φ = 6799680.

The previous prime is 21489631. The next prime is 21489653. The reversal of 21489650 is 5698412.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21489650.

It is not an unprimeable number, because it can be changed into a prime (21489653) 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, 2189 + ... + 6911.

It is an arithmetic number, because the mean of its divisors is an integer number (1025108).

Almost surely, 2^21489650 is an apocalyptic number.

21489650 is an abundant number, since it is smaller than the sum of its proper divisors (27715534).

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

21489650 is a wasteful number, since it uses less digits than its factorization.

21489650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4755 (or 4750 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 21489650 is about 4635.6930441952. The cubic root of 21489650 is about 278.0202614496.

The spelling of 21489650 in words is "twenty-one million, four hundred eighty-nine thousand, six hundred fifty".