21274742077 has 2 divisors, whose sum is σ = 21274742078. Its totient is φ = 21274742076.

The previous prime is 21274742063. The next prime is 21274742117. The reversal of 21274742077 is 77024747212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14575974361 + 6698767716 = 120731^2 + 81846^2 .

It is a cyclic number.

It is not a de Polignac number, because 21274742077 - 2¹¹ = 21274740029 is a prime.

It is a super-2 number, since 2×21274742077² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21272742077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10637371038 + 10637371039.

It is an arithmetic number, because the mean of its divisors is an integer number (10637371039).

Almost surely, 2^21274742077 is an apocalyptic number.

It is an amenable number.

21274742077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21274742077 is an equidigital number, since it uses as much as digits as its factorization.

21274742077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 307328, while the sum is 43.

The spelling of 21274742077 in words is "twenty-one billion, two hundred seventy-four million, seven hundred forty-two thousand, seventy-seven".