1391279256 has 192 divisors, whose sum is σ = 4178304000. Its totient is φ = 416482560.

The previous prime is 1391279249. The next prime is 1391279273. The reversal of 1391279256 is 6529721931.

It is a happy number.

1391279256 is a `hidden beast` number, since 1 + 391 + 2 + 7 + 9 + 256 = 666.

1391279256 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×1391279256³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2247315 + ... + 2247933.

It is an arithmetic number, because the mean of its divisors is an integer number (21762000).

Almost surely, 2^1391279256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1391279256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2089152000).

1391279256 is an abundant number, since it is smaller than the sum of its proper divisors (2787024744).

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

1391279256 is a wasteful number, since it uses less digits than its factorization.

1391279256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734 (or 727 counting only the distinct ones).

The product of its digits is 204120, while the sum is 45.

The square root of 1391279256 is about 37299.8559782742. The cubic root of 1391279256 is about 1116.3612928197.

The spelling of 1391279256 in words is "one billion, three hundred ninety-one million, two hundred seventy-nine thousand, two hundred fifty-six".