21210501547 has 2 divisors, whose sum is σ = 21210501548. Its totient is φ = 21210501546.

The previous prime is 21210501509. The next prime is 21210501551. The reversal of 21210501547 is 74510501212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21210501547 - 2¹⁵ = 21210468779 is a prime.

It is not a weakly prime, because it can be changed into another prime (21219501547) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605250773 + 10605250774.

It is an arithmetic number, because the mean of its divisors is an integer number (10605250774).

Almost surely, 2^21210501547 is an apocalyptic number.

21210501547 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210501547 is an equidigital number, since it uses as much as digits as its factorization.

21210501547 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2800, while the sum is 28.

The spelling of 21210501547 in words is "twenty-one billion, two hundred ten million, five hundred one thousand, five hundred forty-seven".