21881748 has 48 divisors (see below), whose sum is σ = 58601984. Its totient is φ = 6225120.

The previous prime is 21881723. The next prime is 21881767. The reversal of 21881748 is 84718812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27411 + ... + 28197.

Almost surely, 2^21881748 is an apocalyptic number.

21881748 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21881748 is an abundant number, since it is smaller than the sum of its proper divisors (36720236).

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

21881748 is a wasteful number, since it uses less digits than its factorization.

21881748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1132 (or 1130 counting only the distinct ones).

The product of its digits is 28672, while the sum is 39.

The square root of 21881748 is about 4677.7930693865. The cubic root of 21881748 is about 279.7009903275.

The spelling of 21881748 in words is "twenty-one million, eight hundred eighty-one thousand, seven hundred forty-eight".