28464421 has 2 divisors, whose sum is σ = 28464422. Its totient is φ = 28464420.

The previous prime is 28464419. The next prime is 28464427. The reversal of 28464421 is 12446482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18922500 + 9541921 = 4350^2 + 3089^2 .

It is a cyclic number.

It is not a de Polignac number, because 28464421 - 2¹ = 28464419 is a prime.

Together with 28464419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28464427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14232210 + 14232211.

It is an arithmetic number, because the mean of its divisors is an integer number (14232211).

Almost surely, 2^28464421 is an apocalyptic number.

It is an amenable number.

28464421 is a deficient number, since it is larger than the sum of its proper divisors (1).

28464421 is an equidigital number, since it uses as much as digits as its factorization.

28464421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12288, while the sum is 31.

The square root of 28464421 is about 5335.2058067145. The cubic root of 28464421 is about 305.3285753990.

The spelling of 28464421 in words is "twenty-eight million, four hundred sixty-four thousand, four hundred twenty-one".