21303547057 has 4 divisors (see below), whose sum is σ = 22942281460. Its totient is φ = 19664812656.

The previous prime is 21303547039. The next prime is 21303547081. The reversal of 21303547057 is 75074530312.

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 6617985201 + 14685561856 = 81351^2 + 121184^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21303547057 is a prime.

It is a super-2 number, since 2×21303547057² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21303547037) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 819367182 + ... + 819367207.

It is an arithmetic number, because the mean of its divisors is an integer number (5735570365).

Almost surely, 2^21303547057 is an apocalyptic number.

It is an amenable number.

21303547057 is a deficient number, since it is larger than the sum of its proper divisors (1638734403).

21303547057 is a wasteful number, since it uses less digits than its factorization.

21303547057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1638734402.

The product of its (nonzero) digits is 88200, while the sum is 37.

The spelling of 21303547057 in words is "twenty-one billion, three hundred three million, five hundred forty-seven thousand, fifty-seven".