1261670740 has 96 divisors (see below), whose sum is σ = 2976994944. Its totient is φ = 445186560.

The previous prime is 1261670731. The next prime is 1261670741. The reversal of 1261670740 is 470761621.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1261670696 and 1261670705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261670741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1863282 + ... + 1863958.

It is an arithmetic number, because the mean of its divisors is an integer number (31010364).

Almost surely, 2^1261670740 is an apocalyptic number.

1261670740 is a gapful number since it is divisible by the number (10) 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 1261670740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1488497472).

1261670740 is an abundant number, since it is smaller than the sum of its proper divisors (1715324204).

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

1261670740 is a wasteful number, since it uses less digits than its factorization.

1261670740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937 (or 935 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 34.

The square root of 1261670740 is about 35520.0047860357. The cubic root of 1261670740 is about 1080.5594780676.

The spelling of 1261670740 in words is "one billion, two hundred sixty-one million, six hundred seventy thousand, seven hundred forty".