21751293877 has 2 divisors, whose sum is σ = 21751293878. Its totient is φ = 21751293876.

The previous prime is 21751293869. The next prime is 21751293881. The reversal of 21751293877 is 77839215712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21694049521 + 57244356 = 147289^2 + 7566^2 .

It is a cyclic number.

It is not a de Polignac number, because 21751293877 - 2³ = 21751293869 is a prime.

It is a super-2 number, since 2×21751293877² (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 (21751293827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10875646938 + 10875646939.

It is an arithmetic number, because the mean of its divisors is an integer number (10875646939).

Almost surely, 2^21751293877 is an apocalyptic number.

It is an amenable number.

21751293877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21751293877 is an equidigital number, since it uses as much as digits as its factorization.

21751293877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1481760, while the sum is 52.

The spelling of 21751293877 in words is "twenty-one billion, seven hundred fifty-one million, two hundred ninety-three thousand, eight hundred seventy-seven".