21478932289 has 2 divisors, whose sum is σ = 21478932290. Its totient is φ = 21478932288.

The previous prime is 21478932259. The next prime is 21478932323. The reversal of 21478932289 is 98223987412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21386137600 + 92794689 = 146240^2 + 9633^2 .

It is a cyclic number.

It is not a de Polignac number, because 21478932289 - 2⁵ = 21478932257 is a prime.

It is a super-2 number, since 2×21478932289² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21478932239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10739466144 + 10739466145.

It is an arithmetic number, because the mean of its divisors is an integer number (10739466145).

Almost surely, 2^21478932289 is an apocalyptic number.

It is an amenable number.

21478932289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21478932289 is an equidigital number, since it uses as much as digits as its factorization.

21478932289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3483648, while the sum is 55.

The spelling of 21478932289 in words is "twenty-one billion, four hundred seventy-eight million, nine hundred thirty-two thousand, two hundred eighty-nine".