21164270077 has 2 divisors, whose sum is σ = 21164270078. Its totient is φ = 21164270076.

The previous prime is 21164270021. The next prime is 21164270117. The reversal of 21164270077 is 77007246112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17426904121 + 3737365956 = 132011^2 + 61134^2 .

It is a cyclic number.

It is not a de Polignac number, because 21164270077 - 2¹¹ = 21164268029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21164210077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10582135038 + 10582135039.

It is an arithmetic number, because the mean of its divisors is an integer number (10582135039).

Almost surely, 2^21164270077 is an apocalyptic number.

It is an amenable number.

21164270077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21164270077 is an equidigital number, since it uses as much as digits as its factorization.

21164270077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32928, while the sum is 37.

The spelling of 21164270077 in words is "twenty-one billion, one hundred sixty-four million, two hundred seventy thousand, seventy-seven".