21412421377 has 2 divisors, whose sum is σ = 21412421378. Its totient is φ = 21412421376.

The previous prime is 21412421323. The next prime is 21412421447. The reversal of 21412421377 is 77312421412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18801620161 + 2610801216 = 137119^2 + 51096^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21412421377 is a prime.

It is a super-2 number, since 2×21412421377² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21412401377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10706210688 + 10706210689.

It is an arithmetic number, because the mean of its divisors is an integer number (10706210689).

Almost surely, 2^21412421377 is an apocalyptic number.

It is an amenable number.

21412421377 is a deficient number, since it is larger than the sum of its proper divisors (1).

21412421377 is an equidigital number, since it uses as much as digits as its factorization.

21412421377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18816, while the sum is 34.

Adding to 21412421377 its reverse (77312421412), we get a palindrome (98724842789).

The spelling of 21412421377 in words is "twenty-one billion, four hundred twelve million, four hundred twenty-one thousand, three hundred seventy-seven".