28779691 has 8 divisors (see below), whose sum is σ = 30533760. Its totient is φ = 27032448.

The previous prime is 28779679. The next prime is 28779697. The reversal of 28779691 is 19697782.

It is a happy number.

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

It is not a de Polignac number, because 28779691 - 2¹³ = 28771499 is a prime.

It is a super-2 number, since 2×28779691² = 1656541228110962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28779697) 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, 8925 + ... + 11713.

It is an arithmetic number, because the mean of its divisors is an integer number (3816720).

Almost surely, 2^28779691 is an apocalyptic number.

28779691 is a deficient number, since it is larger than the sum of its proper divisors (1754069).

28779691 is a wasteful number, since it uses less digits than its factorization.

28779691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3413.

The product of its digits is 381024, while the sum is 49.

The square root of 28779691 is about 5364.6706329466. The cubic root of 28779691 is about 306.4517051894.

The spelling of 28779691 in words is "twenty-eight million, seven hundred seventy-nine thousand, six hundred ninety-one".