21321451047 has 16 divisors (see below), whose sum is σ = 30658037760. Its totient is φ = 13102626912.

The previous prime is 21321451013. The next prime is 21321451069. The reversal of 21321451047 is 74015412312.

It is not a de Polignac number, because 21321451047 - 2²⁸ = 21053015591 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21321451147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 352143 + ... + 408224.

It is an arithmetic number, because the mean of its divisors is an integer number (1916127360).

Almost surely, 2^21321451047 is an apocalyptic number.

21321451047 is a deficient number, since it is larger than the sum of its proper divisors (9336586713).

21321451047 is a wasteful number, since it uses less digits than its factorization.

21321451047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761102.

The product of its (nonzero) digits is 6720, while the sum is 30.

Adding to 21321451047 its reverse (74015412312), we get a palindrome (95336863359).

The spelling of 21321451047 in words is "twenty-one billion, three hundred twenty-one million, four hundred fifty-one thousand, forty-seven".