28057015978 has 8 divisors (see below), whose sum is σ = 42318041220. Its totient is φ = 13951002240.

The previous prime is 28057015963. The next prime is 28057015981. The reversal of 28057015978 is 87951075082.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16963239049 + 11093776929 = 130243^2 + 105327^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×28057015978² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38752423 + ... + 38753146.

Almost surely, 2^28057015978 is an apocalyptic number.

28057015978 is a deficient number, since it is larger than the sum of its proper divisors (14261025242).

28057015978 is a wasteful number, since it uses less digits than its factorization.

28057015978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77505752.

The product of its (nonzero) digits is 1411200, while the sum is 52.

The spelling of 28057015978 in words is "twenty-eight billion, fifty-seven million, fifteen thousand, nine hundred seventy-eight".