28471987 has 2 divisors, whose sum is σ = 28471988. Its totient is φ = 28471986.

The previous prime is 28471979. The next prime is 28472021. The reversal of 28471987 is 78917482.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28471987 - 2³ = 28471979 is a prime.

It is not a weakly prime, because it can be changed into another prime (28471967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14235993 + 14235994.

It is an arithmetic number, because the mean of its divisors is an integer number (14235994).

Almost surely, 2^28471987 is an apocalyptic number.

28471987 is a deficient number, since it is larger than the sum of its proper divisors (1).

28471987 is an equidigital number, since it uses as much as digits as its factorization.

28471987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 225792, while the sum is 46.

The square root of 28471987 is about 5335.9148231583. The cubic root of 28471987 is about 305.3556256753.

The spelling of 28471987 in words is "twenty-eight million, four hundred seventy-one thousand, nine hundred eighty-seven".