28291980 has 24 divisors (see below), whose sum is σ = 79217712. Its totient is φ = 7544512.

The previous prime is 28291973. The next prime is 28291999. The reversal of 28291980 is 8919282.

It is a super-2 number, since 2×28291980² = 1600872264640800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235707 + ... + 235826.

It is an arithmetic number, because the mean of its divisors is an integer number (3300738).

Almost surely, 2^28291980 is an apocalyptic number.

28291980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28291980 is an abundant number, since it is smaller than the sum of its proper divisors (50925732).

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

28291980 is a wasteful number, since it uses less digits than its factorization.

28291980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471545 (or 471543 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 28291980 is about 5319.0205865366. The cubic root of 28291980 is about 304.7107532812.

The spelling of 28291980 in words is "twenty-eight million, two hundred ninety-one thousand, nine hundred eighty".