1261946790 has 320 divisors, whose sum is σ = 3893218560. Its totient is φ = 291133440.

The previous prime is 1261946789. The next prime is 1261946813. The reversal of 1261946790 is 976491621.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 15973971 + ... + 15974049.

It is an arithmetic number, because the mean of its divisors is an integer number (12166308).

Almost surely, 2^1261946790 is an apocalyptic number.

1261946790 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261946790, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1946609280).

1261946790 is an abundant number, since it is smaller than the sum of its proper divisors (2631271770).

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

1261946790 is a wasteful number, since it uses less digits than its factorization.

1261946790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189 (or 180 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 45.

The square root of 1261946790 is about 35523.8904119467. The cubic root of 1261946790 is about 1080.6382801095.

The spelling of 1261946790 in words is "one billion, two hundred sixty-one million, nine hundred forty-six thousand, seven hundred ninety".