21677240 has 32 divisors (see below), whose sum is σ = 52526880. Its totient is φ = 8003712.

The previous prime is 21677231. The next prime is 21677251. The reversal of 21677240 is 4277612.

It is a congruent number.

It is an unprimeable number.

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, 20324 + ... + 21363.

It is an arithmetic number, because the mean of its divisors is an integer number (1641465).

Almost surely, 2^21677240 is an apocalyptic number.

21677240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21677240 is an abundant number, since it is smaller than the sum of its proper divisors (30849640).

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

21677240 is a wasteful number, since it uses less digits than its factorization.

21677240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41711 (or 41707 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 21677240 is about 4655.8823009178. The cubic root of 21677240 is about 278.8268946703.

The spelling of 21677240 in words is "twenty-one million, six hundred seventy-seven thousand, two hundred forty".