1278437378461 has 24 divisors (see below), whose sum is σ = 1363844218784. Its totient is φ = 1198119548160.

The previous prime is 1278437378459. The next prime is 1278437378467. The reversal of 1278437378461 is 1648737348721.

It is a happy number.

It is not a de Polignac number, because 1278437378461 - 2¹ = 1278437378459 is a prime.

It is a super-3 number, since 3×1278437378461³ (a number of 37 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (61) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1278437378461.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278437378467) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 132571906 + ... + 132581548.

Almost surely, 2^{1278437378461} is an apocalyptic number.

It is an amenable number.

1278437378461 is a deficient number, since it is larger than the sum of its proper divisors (85406840323).

1278437378461 is a wasteful number, since it uses less digits than its factorization.

1278437378461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11581 (or 11564 counting only the distinct ones).

The product of its digits is 37933056, while the sum is 61.

The spelling of 1278437378461 in words is "one trillion, two hundred seventy-eight billion, four hundred thirty-seven million, three hundred seventy-eight thousand, four hundred sixty-one".