21311301532021 has 4 divisors (see below), whose sum is σ = 21324513747852. Its totient is φ = 21298089316192.

The previous prime is 21311301531991. The next prime is 21311301532069. The reversal of 21311301532021 is 12023510311312.

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 4230323400625 + 17080978131396 = 2056775^2 + 4132914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311301532021 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 (21311301532421) 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, 6606105496 + ... + 6606108721.

It is an arithmetic number, because the mean of its divisors is an integer number (5331128436963).

Almost surely, 2^{21311301532021} is an apocalyptic number.

It is an amenable number.

21311301532021 is a deficient number, since it is larger than the sum of its proper divisors (13212215831).

21311301532021 is a wasteful number, since it uses less digits than its factorization.

21311301532021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13212215830.

The product of its (nonzero) digits is 1080, while the sum is 25.

Adding to 21311301532021 its reverse (12023510311312), we get a palindrome (33334811843333).

The spelling of 21311301532021 in words is "twenty-one trillion, three hundred eleven billion, three hundred one million, five hundred thirty-two thousand, twenty-one".