21248601813 has 6 divisors (see below), whose sum is σ = 30692424854. Its totient is φ = 14165734536.

The previous prime is 21248601811. The next prime is 21248601887. The reversal of 21248601813 is 31810684212.

21248601813 is a `hidden beast` number, since 2 + 1 + 2 + 48 + 601 + 8 + 1 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13786751889 + 7461849924 = 117417^2 + 86382^2 .

It is not a de Polignac number, because 21248601813 - 2¹ = 21248601811 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21248601811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1180477870 + ... + 1180477887.

Almost surely, 2^21248601813 is an apocalyptic number.

It is an amenable number.

21248601813 is a deficient number, since it is larger than the sum of its proper divisors (9443823041).

21248601813 is a wasteful number, since it uses less digits than its factorization.

21248601813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2360955763 (or 2360955760 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 21248601813 in words is "twenty-one billion, two hundred forty-eight million, six hundred one thousand, eight hundred thirteen".