291428 has 12 divisors (see below), whose sum is σ = 522732. Its totient is φ = 142080.

The previous prime is 291419. The next prime is 291437. The reversal of 291428 is 824192.

It is an interprime number because it is at equal distance from previous prime (291419) and next prime (291437).

It can be written as a sum of positive squares in 2 ways, for example, as 68644 + 222784 = 262^2 + 472^2 .

It is a junction number, because it is equal to n+sod(n) for n = 291397 and 291406.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291428.

It is an unprimeable number.

291428 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 725 + ... + 1052.

It is an arithmetic number, because the mean of its divisors is an integer number (43561).

2²⁹¹⁴²⁸ is an apocalyptic number.

It is an amenable number.

291428 is a deficient number, since it is larger than the sum of its proper divisors (231304).

291428 is a wasteful number, since it uses less digits than its factorization.

291428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1822 (or 1820 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 291428 is about 539.8407172491. The cubic root of 291428 is about 66.2995262750.

The spelling of 291428 in words is "two hundred ninety-one thousand, four hundred twenty-eight".