1278049981 has 16 divisors (see below), whose sum is σ = 1438542000. Its totient is φ = 1127282688.

The previous prime is 1278049937. The next prime is 1278050063. The reversal of 1278049981 is 1899408721.

It can be written as a sum of positive squares in 8 ways, for example, as 292717881 + 985332100 = 17109^2 + 31390^2 .

It is a cyclic number.

It is not a de Polignac number, because 1278049981 - 2¹³ = 1278041789 is a prime.

It is a super-2 number, since 2×1278049981² = 3266823507868200722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278049181) 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, 19095 + ... + 54043.

It is an arithmetic number, because the mean of its divisors is an integer number (89908875).

Almost surely, 2^1278049981 is an apocalyptic number.

It is an amenable number.

1278049981 is a deficient number, since it is larger than the sum of its proper divisors (160492019).

1278049981 is a wasteful number, since it uses less digits than its factorization.

1278049981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35088.

The product of its (nonzero) digits is 290304, while the sum is 49.

The square root of 1278049981 is about 35749.8249086621. The cubic root of 1278049981 is about 1085.2153949540.

The spelling of 1278049981 in words is "one billion, two hundred seventy-eight million, forty-nine thousand, nine hundred eighty-one".