28692981 has 16 divisors (see below), whose sum is σ = 43312320. Its totient is φ = 18766800.

The previous prime is 28692973. The next prime is 28693001. The reversal of 28692981 is 18929682.

It is not a de Polignac number, because 28692981 - 2³ = 28692973 is a prime.

It is a super-2 number, since 2×28692981² = 1646574317332722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28692901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8595 + ... + 11456.

It is an arithmetic number, because the mean of its divisors is an integer number (2707020).

Almost surely, 2^28692981 is an apocalyptic number.

It is an amenable number.

28692981 is a deficient number, since it is larger than the sum of its proper divisors (14619339).

28692981 is a wasteful number, since it uses less digits than its factorization.

28692981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20113 (or 20107 counting only the distinct ones).

The product of its digits is 124416, while the sum is 45.

The square root of 28692981 is about 5356.5829593128. The cubic root of 28692981 is about 306.1436273079.

The spelling of 28692981 in words is "twenty-eight million, six hundred ninety-two thousand, nine hundred eighty-one".