20521758451 has 2 divisors, whose sum is σ = 20521758452. Its totient is φ = 20521758450.

The previous prime is 20521758371. The next prime is 20521758457. The reversal of 20521758451 is 15485712502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20521758451 - 2⁹ = 20521757939 is a prime.

It is a super-2 number, since 2×20521758451² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20521758457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10260879225 + 10260879226.

It is an arithmetic number, because the mean of its divisors is an integer number (10260879226).

Almost surely, 2^20521758451 is an apocalyptic number.

20521758451 is a deficient number, since it is larger than the sum of its proper divisors (1).

20521758451 is an equidigital number, since it uses as much as digits as its factorization.

20521758451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112000, while the sum is 40.

The spelling of 20521758451 in words is "twenty billion, five hundred twenty-one million, seven hundred fifty-eight thousand, four hundred fifty-one".