21001253027 has 2 divisors, whose sum is σ = 21001253028. Its totient is φ = 21001253026.

The previous prime is 21001253023. The next prime is 21001253041. The reversal of 21001253027 is 72035210012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001253027 - 2² = 21001253023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001252993 and 21001253011.

It is not a weakly prime, because it can be changed into another prime (21001253023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500626513 + 10500626514.

It is an arithmetic number, because the mean of its divisors is an integer number (10500626514).

Almost surely, 2^21001253027 is an apocalyptic number.

21001253027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001253027 is an equidigital number, since it uses as much as digits as its factorization.

21001253027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 23.

Adding to 21001253027 its reverse (72035210012), we get a palindrome (93036463039).

The spelling of 21001253027 in words is "twenty-one billion, one million, two hundred fifty-three thousand, twenty-seven".