21010587 has 24 divisors (see below), whose sum is σ = 31402800. Its totient is φ = 12475008.

The previous prime is 21010579. The next prime is 21010601. The reversal of 21010587 is 78501012.

It is not a de Polignac number, because 21010587 - 2³ = 21010579 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21010547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13989 + ... + 15417.

It is an arithmetic number, because the mean of its divisors is an integer number (1308450).

Almost surely, 2^21010587 is an apocalyptic number.

21010587 is a deficient number, since it is larger than the sum of its proper divisors (10392213).

21010587 is a wasteful number, since it uses less digits than its factorization.

21010587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1487 (or 1474 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 21010587 is about 4583.7306858060. The cubic root of 21010587 is about 275.9387729130.

Adding to 21010587 its reverse (78501012), we get a palindrome (99511599).

The spelling of 21010587 in words is "twenty-one million, ten thousand, five hundred eighty-seven".