21587048 has 32 divisors (see below), whose sum is σ = 47208000. Its totient is φ = 9250416.

The previous prime is 21587023. The next prime is 21587057. The reversal of 21587048 is 84078512.

It is a junction number, because it is equal to n+sod(n) for n = 21586999 and 21587017.

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, 1190 + ... + 6677.

It is an arithmetic number, because the mean of its divisors is an integer number (1475250).

Almost surely, 2^21587048 is an apocalyptic number.

21587048 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21587048 is an abundant number, since it is smaller than the sum of its proper divisors (25620952).

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

21587048 is an equidigital number, since it uses as much as digits as its factorization.

21587048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7894 (or 7876 counting only the distinct ones).

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 21587048 is about 4646.1863931616. The cubic root of 21587048 is about 278.4396542031.

The spelling of 21587048 in words is "twenty-one million, five hundred eighty-seven thousand, forty-eight".