28912913 has 8 divisors (see below), whose sum is σ = 30640680. Its totient is φ = 27233920.

The previous prime is 28912883. The next prime is 28912951. The reversal of 28912913 is 31921982.

It can be written as a sum of positive squares in 4 ways, for example, as 1329409 + 27583504 = 1153^2 + 5252^2 .

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 28912913 - 2¹⁰ = 28911889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28932913) 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, 10970 + ... + 13347.

It is an arithmetic number, because the mean of its divisors is an integer number (3830085).

Almost surely, 2^28912913 is an apocalyptic number.

It is an amenable number.

28912913 is a deficient number, since it is larger than the sum of its proper divisors (1727767).

28912913 is a wasteful number, since it uses less digits than its factorization.

28912913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24387.

The product of its digits is 7776, while the sum is 35.

The square root of 28912913 is about 5377.0729026116. The cubic root of 28912913 is about 306.9238352933.

The spelling of 28912913 in words is "twenty-eight million, nine hundred twelve thousand, nine hundred thirteen".