21020000087 has 2 divisors, whose sum is σ = 21020000088. Its totient is φ = 21020000086.

The previous prime is 21020000083. The next prime is 21020000119. The reversal of 21020000087 is 78000002012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020000087 - 2² = 21020000083 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020000083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510000043 + 10510000044.

It is an arithmetic number, because the mean of its divisors is an integer number (10510000044).

Almost surely, 2^21020000087 is an apocalyptic number.

21020000087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020000087 is an equidigital number, since it uses as much as digits as its factorization.

21020000087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21020000087 its reverse (78000002012), we get a palindrome (99020002099).

The spelling of 21020000087 in words is "twenty-one billion, twenty million, eighty-seven", and thus it is an aban number and an uban number.