11978478261 has 16 divisors (see below), whose sum is σ = 17748057600. Its totient is φ = 7984678464.

The previous prime is 11978478257. The next prime is 11978478277. The reversal of 11978478261 is 16287487911.

It is not a de Polignac number, because 11978478261 - 2² = 11978478257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11978478198 and 11978478207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11978478221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 250125 + ... + 294141.

It is an arithmetic number, because the mean of its divisors is an integer number (1109253600).

Almost surely, 2^11978478261 is an apocalyptic number.

It is an amenable number.

11978478261 is a deficient number, since it is larger than the sum of its proper divisors (5769579339).

11978478261 is a wasteful number, since it uses less digits than its factorization.

11978478261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54105 (or 54099 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The spelling of 11978478261 in words is "eleven billion, nine hundred seventy-eight million, four hundred seventy-eight thousand, two hundred sixty-one".