278487987 has 8 divisors (see below), whose sum is σ = 372489936. Its totient is φ = 185072352.

The previous prime is 278487977. The next prime is 278488037. The reversal of 278487987 is 789784872.

It is a happy number.

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

It is not a de Polignac number, because 278487987 - 2⁴ = 278487971 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 278487987.

It is not an unprimeable number, because it can be changed into a prime (278487907) 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, 145468 + ... + 147369.

It is an arithmetic number, because the mean of its divisors is an integer number (46561242).

Almost surely, 2^278487987 is an apocalyptic number.

278487987 is a deficient number, since it is larger than the sum of its proper divisors (94001949).

278487987 is a wasteful number, since it uses less digits than its factorization.

278487987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293157.

The product of its digits is 12644352, while the sum is 60.

The square root of 278487987 is about 16687.9593419927. The cubic root of 278487987 is about 653.0335419718.

The spelling of 278487987 in words is "two hundred seventy-eight million, four hundred eighty-seven thousand, nine hundred eighty-seven".