278930991021 has 16 divisors (see below), whose sum is σ = 382468270848. Its totient is φ = 180687240000.

The previous prime is 278930990999. The next prime is 278930991029. The reversal of 278930991021 is 120199039872.

It is not a de Polignac number, because 278930991021 - 2⁷ = 278930990893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (278930991029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1589670 + ... + 1756391.

It is an arithmetic number, because the mean of its divisors is an integer number (23904266928).

Almost surely, 2^278930991021 is an apocalyptic number.

It is an amenable number.

278930991021 is a deficient number, since it is larger than the sum of its proper divisors (103537279827).

278930991021 is a wasteful number, since it uses less digits than its factorization.

278930991021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3346852.

The product of its (nonzero) digits is 489888, while the sum is 51.

The spelling of 278930991021 in words is "two hundred seventy-eight billion, nine hundred thirty million, nine hundred ninety-one thousand, twenty-one".