1256165542 has 8 divisors (see below), whose sum is σ = 1885693896. Its totient is φ = 627600912.

The previous prime is 1256165489. The next prime is 1256165549. The reversal of 1256165542 is 2455616521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1256165549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237663 + ... + 242890.

It is an arithmetic number, because the mean of its divisors is an integer number (235711737).

Almost surely, 2^1256165542 is an apocalyptic number.

1256165542 is a deficient number, since it is larger than the sum of its proper divisors (629528354).

1256165542 is a wasteful number, since it uses less digits than its factorization.

1256165542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481862.

The product of its digits is 72000, while the sum is 37.

The square root of 1256165542 is about 35442.4257352682. The cubic root of 1256165542 is about 1078.9855420322.

The spelling of 1256165542 in words is "one billion, two hundred fifty-six million, one hundred sixty-five thousand, five hundred forty-two".