21206057513473 has 4 divisors (see below), whose sum is σ = 24235494301120. Its totient is φ = 18176620725828.

The previous prime is 21206057513383. The next prime is 21206057513489. The reversal of 21206057513473 is 37431575060212.

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 21206057513473 - 2³⁷ = 21068618560001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21206057513873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1514718393813 + ... + 1514718393826.

It is an arithmetic number, because the mean of its divisors is an integer number (6058873575280).

Almost surely, 2^{21206057513473} is an apocalyptic number.

It is an amenable number.

21206057513473 is a deficient number, since it is larger than the sum of its proper divisors (3029436787647).

21206057513473 is an equidigital number, since it uses as much as digits as its factorization.

21206057513473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3029436787646.

The product of its (nonzero) digits is 1058400, while the sum is 46.

The spelling of 21206057513473 in words is "twenty-one trillion, two hundred six billion, fifty-seven million, five hundred thirteen thousand, four hundred seventy-three".