21027077 has 2 divisors, whose sum is σ = 21027078. Its totient is φ = 21027076.

The previous prime is 21027073. The next prime is 21027103. The reversal of 21027077 is 77072012.

It is an a-pointer prime, because the next prime (21027103) can be obtained adding 21027077 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19589476 + 1437601 = 4426^2 + 1199^2 .

It is a cyclic number.

It is not a de Polignac number, because 21027077 - 2² = 21027073 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21027073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10513538 + 10513539.

It is an arithmetic number, because the mean of its divisors is an integer number (10513539).

Almost surely, 2^21027077 is an apocalyptic number.

It is an amenable number.

21027077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21027077 is an equidigital number, since it uses as much as digits as its factorization.

21027077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1372, while the sum is 26.

The square root of 21027077 is about 4585.5290861579. The cubic root of 21027077 is about 276.0109435204.

Adding to 21027077 its reverse (77072012), we get a palindrome (98099089).

The spelling of 21027077 in words is "twenty-one million, twenty-seven thousand, seventy-seven".