11978278731225 has 81 divisors (see below), whose sum is σ = 21591705592093. Its totient is φ = 6347797438080.

The previous prime is 11978278731197. The next prime is 11978278731269. The reversal of 11978278731225 is 52213787287911.

The square root of 11978278731225 is 3460965.

It is a perfect power (a square), and thus also a powerful number.

11978278731225 is a `hidden beast` number, since 1 + 1 + 9 + 78 + 278 + 73 + 1 + 225 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 445544235081 + 11532734496144 = 667491^2 + 3395988^2 .

It is not a de Polignac number, because 11978278731225 - 2³³ = 11969688796633 is a prime.

It is a super-2 number, since 2×11978278731225² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 9292690381 + ... + 9292691669.

Almost surely, 2^{11978278731225} is an apocalyptic number.

11978278731225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

11978278731225 is the 3460965-th square number.

11978278731225 is the 1730483-rd centered octagonal number.

It is an amenable number.

11978278731225 is a deficient number, since it is larger than the sum of its proper divisors (9613426860868).

11978278731225 is an frugal number, since it uses more digits than its factorization.

11978278731225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2952 (or 1476 counting only the distinct ones).

The product of its digits is 23708160, while the sum is 63.

The spelling of 11978278731225 in words is "eleven trillion, nine hundred seventy-eight billion, two hundred seventy-eight million, seven hundred thirty-one thousand, two hundred twenty-five".