21247464 has 32 divisors (see below), whose sum is σ = 60707520. Its totient is φ = 6070656.

The previous prime is 21247463. The next prime is 21247483. The reversal of 21247464 is 46474212.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21247463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63069 + ... + 63404.

It is an arithmetic number, because the mean of its divisors is an integer number (1897110).

Almost surely, 2^21247464 is an apocalyptic number.

21247464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21247464 is an abundant number, since it is smaller than the sum of its proper divisors (39460056).

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

21247464 is a wasteful number, since it uses less digits than its factorization.

21247464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126489 (or 126485 counting only the distinct ones).

The product of its digits is 10752, while the sum is 30.

The square root of 21247464 is about 4609.4971526187. The cubic root of 21247464 is about 276.9718939105.

The spelling of 21247464 in words is "twenty-one million, two hundred forty-seven thousand, four hundred sixty-four".