21478304473 has 2 divisors, whose sum is σ = 21478304474. Its totient is φ = 21478304472.

The previous prime is 21478304467. The next prime is 21478304489. The reversal of 21478304473 is 37440387412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11421624384 + 10056680089 = 106872^2 + 100283^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21478304473 is a prime.

It is a super-2 number, since 2×21478304473² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21478304873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10739152236 + 10739152237.

It is an arithmetic number, because the mean of its divisors is an integer number (10739152237).

Almost surely, 2^21478304473 is an apocalyptic number.

It is an amenable number.

21478304473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21478304473 is an equidigital number, since it uses as much as digits as its factorization.

21478304473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 451584, while the sum is 43.

The spelling of 21478304473 in words is "twenty-one billion, four hundred seventy-eight million, three hundred four thousand, four hundred seventy-three".