21035501213 has 4 divisors (see below), whose sum is σ = 21060047580. Its totient is φ = 21010954848.

The previous prime is 21035501131. The next prime is 21035501237. The reversal of 21035501213 is 31210553012.

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 18403092964 + 2632408249 = 135658^2 + 51307^2 .

It is a cyclic number.

It is not a de Polignac number, because 21035501213 - 2²⁴ = 21018723997 is a prime.

It is a super-2 number, since 2×21035501213² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21035501273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12271898 + ... + 12273611.

It is an arithmetic number, because the mean of its divisors is an integer number (5265011895).

Almost surely, 2^21035501213 is an apocalyptic number.

It is an amenable number.

21035501213 is a deficient number, since it is larger than the sum of its proper divisors (24546367).

21035501213 is an equidigital number, since it uses as much as digits as its factorization.

21035501213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24546366.

The product of its (nonzero) digits is 900, while the sum is 23.

The spelling of 21035501213 in words is "twenty-one billion, thirty-five million, five hundred one thousand, two hundred thirteen".