21867040 has 48 divisors (see below), whose sum is σ = 55640088. Its totient is φ = 8073216.

The previous prime is 21867023. The next prime is 21867047. The reversal of 21867040 is 4076812.

It can be written as a sum of positive squares in 4 ways, for example, as 5513104 + 16353936 = 2348^2 + 4044^2 .

It is not an unprimeable number, because it can be changed into a prime (21867047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3177 + ... + 7336.

Almost surely, 2^21867040 is an apocalyptic number.

21867040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21867040 is an abundant number, since it is smaller than the sum of its proper divisors (33773048).

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

21867040 is a wasteful number, since it uses less digits than its factorization.

21867040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10541 (or 10533 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 21867040 is about 4676.2206962461. The cubic root of 21867040 is about 279.6383084944.

The spelling of 21867040 in words is "twenty-one million, eight hundred sixty-seven thousand, forty".