28478947 has 16 divisors (see below), whose sum is σ = 33664000. Its totient is φ = 24078600.

The previous prime is 28478939. The next prime is 28478951. The reversal of 28478947 is 74987482.

It is not a de Polignac number, because 28478947 - 2³ = 28478939 is a prime.

It is a super-2 number, since 2×28478947² = 1622100844457618, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28478947.

It is not an unprimeable number, because it can be changed into a prime (28478917) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26572 + ... + 27622.

It is an arithmetic number, because the mean of its divisors is an integer number (2104000).

Almost surely, 2^28478947 is an apocalyptic number.

28478947 is a deficient number, since it is larger than the sum of its proper divisors (5185053).

28478947 is an equidigital number, since it uses as much as digits as its factorization.

28478947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1151 (or 1137 counting only the distinct ones).

The product of its digits is 903168, while the sum is 49.

The square root of 28478947 is about 5336.5669676300. The cubic root of 28478947 is about 305.3805051238.

The spelling of 28478947 in words is "twenty-eight million, four hundred seventy-eight thousand, nine hundred forty-seven".