28431077 has 4 divisors (see below), whose sum is σ = 28696896. Its totient is φ = 28165260.

The previous prime is 28431071. The next prime is 28431079. The reversal of 28431077 is 77013482.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28431077 is a prime.

It is a super-2 number, since 2×28431077² = 1616652278759858, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28431071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132749 + ... + 132962.

It is an arithmetic number, because the mean of its divisors is an integer number (7174224).

Almost surely, 2^28431077 is an apocalyptic number.

It is an amenable number.

28431077 is a deficient number, since it is larger than the sum of its proper divisors (265819).

28431077 is a wasteful number, since it uses less digits than its factorization.

28431077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265818.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 28431077 is about 5332.0799881472. The cubic root of 28431077 is about 305.2093054047.

The spelling of 28431077 in words is "twenty-eight million, four hundred thirty-one thousand, seventy-seven".