21074580 has 60 divisors (see below), whose sum is σ = 66116820. Its totient is φ = 5619456.

The previous prime is 21074569. The next prime is 21074587. The reversal of 21074580 is 8547012.

21074580 is a `hidden beast` number, since 2 + 10 + 74 + 580 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5817744 + 15256836 = 2412^2 + 3906^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21074587) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4885 + ... + 8124.

It is an arithmetic number, because the mean of its divisors is an integer number (1101947).

Almost surely, 2^21074580 is an apocalyptic number.

21074580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21074580 is an abundant number, since it is smaller than the sum of its proper divisors (45042240).

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

21074580 is a wasteful number, since it uses less digits than its factorization.

21074580 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13030 (or 13019 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 21074580 is about 4590.7058280835. The cubic root of 21074580 is about 276.2186358337.

The spelling of 21074580 in words is "twenty-one million, seventy-four thousand, five hundred eighty".