21371802953 has 4 divisors (see below), whose sum is σ = 21375061968. Its totient is φ = 21368543940.

The previous prime is 21371802941. The next prime is 21371802997. The reversal of 21371802953 is 35920817312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21371802953 - 2⁴ = 21371802937 is a prime.

It is a super-2 number, since 2×21371802953² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21371802953.

It is not an unprimeable number, because it can be changed into a prime (21371802553) 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, 1619651 + ... + 1632792.

It is an arithmetic number, because the mean of its divisors is an integer number (5343765492).

Almost surely, 2^21371802953 is an apocalyptic number.

It is an amenable number.

21371802953 is a deficient number, since it is larger than the sum of its proper divisors (3259015).

21371802953 is an equidigital number, since it uses as much as digits as its factorization.

21371802953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3259014.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 21371802953 in words is "twenty-one billion, three hundred seventy-one million, eight hundred two thousand, nine hundred fifty-three".