2787000021 has 64 divisors (see below), whose sum is σ = 4642444800. Its totient is φ = 1640604672.

The previous prime is 2787000017. The next prime is 2787000053. The reversal of 2787000021 is 1200007872.

It is not a de Polignac number, because 2787000021 - 2² = 2787000017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2787000001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1149016 + ... + 1151438.

It is an arithmetic number, because the mean of its divisors is an integer number (72538200).

Almost surely, 2^2787000021 is an apocalyptic number.

It is an amenable number.

2787000021 is a deficient number, since it is larger than the sum of its proper divisors (1855444779).

2787000021 is a wasteful number, since it uses less digits than its factorization.

2787000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2587 (or 2581 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The square root of 2787000021 is about 52792.0450541556. The cubic root of 2787000021 is about 1407.2750586308.

Adding to 2787000021 its reverse (1200007872), we get a palindrome (3987007893).

The spelling of 2787000021 in words is "two billion, seven hundred eighty-seven million, twenty-one", and thus it is an aban number.