21004680 has 32 divisors (see below), whose sum is σ = 63014400. Its totient is φ = 5601216.

The previous prime is 21004663. The next prime is 21004691. The reversal of 21004680 is 8640012.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 87400 + ... + 87639.

It is an arithmetic number, because the mean of its divisors is an integer number (1969200).

Almost surely, 2^21004680 is an apocalyptic number.

21004680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004680 is an abundant number, since it is smaller than the sum of its proper divisors (42009720).

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

21004680 is a wasteful number, since it uses less digits than its factorization.

21004680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175053 (or 175049 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 21004680 is about 4583.0862963728. The cubic root of 21004680 is about 275.9129109811.

Adding to 21004680 its reverse (8640012), we get a palindrome (29644692).

The spelling of 21004680 in words is "twenty-one million, four thousand, six hundred eighty".