1257121536 has 144 divisors (see below), whose sum is σ = 3706082688. Its totient is φ = 375091200.

The previous prime is 1257121531. The next prime is 1257121573. The reversal of 1257121536 is 6351217521.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 1257121497 and 1257121506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1257121531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 564906 + ... + 567126.

Almost surely, 2^1257121536 is an apocalyptic number.

1257121536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1257121536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1853041344).

1257121536 is an abundant number, since it is smaller than the sum of its proper divisors (2448961152).

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

1257121536 is a wasteful number, since it uses less digits than its factorization.

1257121536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2318 (or 2304 counting only the distinct ones).

The product of its digits is 12600, while the sum is 33.

The square root of 1257121536 is about 35455.9097471776. The cubic root of 1257121536 is about 1079.2591901855.

The spelling of 1257121536 in words is "one billion, two hundred fifty-seven million, one hundred twenty-one thousand, five hundred thirty-six".