278138811402 has 24 divisors (see below), whose sum is σ = 606472531236. Its totient is φ = 92122407936.

The previous prime is 278138811389. The next prime is 278138811403. The reversal of 278138811402 is 204118831872.

It can be written as a sum of positive squares in 2 ways, for example, as 220534491321 + 57604320081 = 469611^2 + 240009^2 .

It is a super-2 number, since 2×278138811402² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (278138811403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49207863 + ... + 49213514.

Almost surely, 2^278138811402 is an apocalyptic number.

278138811402 is an abundant number, since it is smaller than the sum of its proper divisors (328333719834).

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

278138811402 is a wasteful number, since it uses less digits than its factorization.

278138811402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98421542 (or 98421539 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 45.

The spelling of 278138811402 in words is "two hundred seventy-eight billion, one hundred thirty-eight million, eight hundred eleven thousand, four hundred two".