28761978 has 16 divisors (see below), whose sum is σ = 65741760. Its totient is φ = 8217696.

The previous prime is 28761949. The next prime is 28762009. The reversal of 28761978 is 87916782.

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, 342363 + ... + 342446.

It is an arithmetic number, because the mean of its divisors is an integer number (4108860).

Almost surely, 2^28761978 is an apocalyptic number.

28761978 is an abundant number, since it is smaller than the sum of its proper divisors (36979782).

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

28761978 is a wasteful number, since it uses less digits than its factorization.

28761978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684821.

The product of its digits is 338688, while the sum is 48.

The square root of 28761978 is about 5363.0194853273. The cubic root of 28761978 is about 306.3888218056.

The spelling of 28761978 in words is "twenty-eight million, seven hundred sixty-one thousand, nine hundred seventy-eight".