28471621 has 2 divisors, whose sum is σ = 28471622. Its totient is φ = 28471620.

The previous prime is 28471607. The next prime is 28471643. The reversal of 28471621 is 12617482.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20349121 + 8122500 = 4511^2 + 2850^2 .

It is a cyclic number.

It is not a de Polignac number, because 28471621 - 2⁹ = 28471109 is a prime.

It is a super-3 number, since 3×28471621³ (a number of 23 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28471601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14235810 + 14235811.

It is an arithmetic number, because the mean of its divisors is an integer number (14235811).

Almost surely, 2^28471621 is an apocalyptic number.

It is an amenable number.

28471621 is a deficient number, since it is larger than the sum of its proper divisors (1).

28471621 is an equidigital number, since it uses as much as digits as its factorization.

28471621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5376, while the sum is 31.

The square root of 28471621 is about 5335.8805271483. The cubic root of 28471621 is about 305.3543172472.

It can be divided in two parts, 28471 and 621, that added together give a palindrome (29092).

The spelling of 28471621 in words is "twenty-eight million, four hundred seventy-one thousand, six hundred twenty-one".