28979540 has 48 divisors (see below), whose sum is σ = 64447488. Its totient is φ = 10923264.

The previous prime is 28979539. The next prime is 28979551. The reversal of 28979540 is 4597982.

It is a happy number.

It is a super-2 number, since 2×28979540² = 1679627477223200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28979491 and 28979500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33149 + ... + 34011.

It is an arithmetic number, because the mean of its divisors is an integer number (1342656).

Almost surely, 2^28979540 is an apocalyptic number.

28979540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28979540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32223744).

28979540 is an abundant number, since it is smaller than the sum of its proper divisors (35467948).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28979540 is a wasteful number, since it uses less digits than its factorization.

28979540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968 (or 966 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 44.

The square root of 28979540 is about 5383.2648086454. The cubic root of 28979540 is about 307.1594131538.

The spelling of 28979540 in words is "twenty-eight million, nine hundred seventy-nine thousand, five hundred forty".