28292981 has 8 divisors (see below), whose sum is σ = 30337920. Its totient is φ = 26290368.

The previous prime is 28292977. The next prime is 28292983. The reversal of 28292981 is 18929282.

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 28292981 - 2² = 28292977 is a prime.

It is a super-2 number, since 2×28292981² = 1600985547732722, 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 (28292983) 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, 9191 + ... + 11876.

It is an arithmetic number, because the mean of its divisors is an integer number (3792240).

Almost surely, 2^28292981 is an apocalyptic number.

It is an amenable number.

28292981 is a deficient number, since it is larger than the sum of its proper divisors (2044939).

28292981 is a wasteful number, since it uses less digits than its factorization.

28292981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21163.

The product of its digits is 41472, while the sum is 41.

The square root of 28292981 is about 5319.1146819748. The cubic root of 28292981 is about 304.7143469011.

The spelling of 28292981 in words is "twenty-eight million, two hundred ninety-two thousand, nine hundred eighty-one".