21407650 has 24 divisors (see below), whose sum is σ = 43439184. Its totient is φ = 7784400.

The previous prime is 21407647. The next prime is 21407653. The reversal of 21407650 is 5670412.

It is an interprime number because it is at equal distance from previous prime (21407647) and next prime (21407653).

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (21407653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18912 + ... + 20011.

It is an arithmetic number, because the mean of its divisors is an integer number (1809966).

Almost surely, 2^21407650 is an apocalyptic number.

21407650 is an abundant number, since it is smaller than the sum of its proper divisors (22031534).

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

21407650 is a wasteful number, since it uses less digits than its factorization.

21407650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38946 (or 38941 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 21407650 is about 4626.8401744603. The cubic root of 21407650 is about 277.6661883633. Note that the first 3 decimals are identical.

The spelling of 21407650 in words is "twenty-one million, four hundred seven thousand, six hundred fifty".