28731967 has 4 divisors (see below), whose sum is σ = 31343976. Its totient is φ = 26119960.

The previous prime is 28731949. The next prime is 28731973. The reversal of 28731967 is 76913782.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28731967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28731917) 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, 1305988 + ... + 1306009.

It is an arithmetic number, because the mean of its divisors is an integer number (7835994).

Almost surely, 2^28731967 is an apocalyptic number.

28731967 is a deficient number, since it is larger than the sum of its proper divisors (2612009).

28731967 is a wasteful number, since it uses less digits than its factorization.

28731967 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2612008.

The product of its digits is 127008, while the sum is 43.

The square root of 28731967 is about 5360.2207976911. The cubic root of 28731967 is about 306.2822200170.

The spelling of 28731967 in words is "twenty-eight million, seven hundred thirty-one thousand, nine hundred sixty-seven".