21252520313 has 4 divisors (see below), whose sum is σ = 21440595828. Its totient is φ = 21064444800.

The previous prime is 21252520271. The next prime is 21252520321. The reversal of 21252520313 is 31302525212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1934856169 + 19317664144 = 43987^2 + 138988^2 .

It is a cyclic number.

It is not a de Polignac number, because 21252520313 - 2¹⁸ = 21252258169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21252520013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94037588 + ... + 94037813.

It is an arithmetic number, because the mean of its divisors is an integer number (5360148957).

Almost surely, 2^21252520313 is an apocalyptic number.

It is an amenable number.

21252520313 is a deficient number, since it is larger than the sum of its proper divisors (188075515).

21252520313 is a wasteful number, since it uses less digits than its factorization.

21252520313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188075514.

The product of its (nonzero) digits is 3600, while the sum is 26.

The spelling of 21252520313 in words is "twenty-one billion, two hundred fifty-two million, five hundred twenty thousand, three hundred thirteen".