28370381 has 8 divisors (see below), whose sum is σ = 31606680. Its totient is φ = 25284672.

The previous prime is 28370357. The next prime is 28370383. The reversal of 28370381 is 18307382.

It can be written as a sum of positive squares in 4 ways, for example, as 2706025 + 25664356 = 1645^2 + 5066^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28370381 - 2²² = 24176077 is a prime.

It is a super-2 number, since 2×28370381² = 1609757036170322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28370383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37250 + ... + 38003.

It is an arithmetic number, because the mean of its divisors is an integer number (3950835).

Almost surely, 2^28370381 is an apocalyptic number.

It is an amenable number.

28370381 is a deficient number, since it is larger than the sum of its proper divisors (3236299).

28370381 is a wasteful number, since it uses less digits than its factorization.

28370381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75295.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 28370381 is about 5326.3853596975. The cubic root of 28370381 is about 304.9919589388.

The spelling of 28370381 in words is "twenty-eight million, three hundred seventy thousand, three hundred eighty-one".