1261666426 has 8 divisors (see below), whose sum is σ = 1974782304. Its totient is φ = 603405660.

The previous prime is 1261666423. The next prime is 1261666433. The reversal of 1261666426 is 6246661621.

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

It is a super-2 number, since 2×1261666426² = 3183604340991226952, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1261666423) 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, 13713720 + ... + 13713811.

It is an arithmetic number, because the mean of its divisors is an integer number (246847788).

Almost surely, 2^1261666426 is an apocalyptic number.

1261666426 is a deficient number, since it is larger than the sum of its proper divisors (713115878).

1261666426 is a wasteful number, since it uses less digits than its factorization.

1261666426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27427556.

The product of its digits is 124416, while the sum is 40.

The square root of 1261666426 is about 35519.9440596406. The cubic root of 1261666426 is about 1080.5582464893.

The spelling of 1261666426 in words is "one billion, two hundred sixty-one million, six hundred sixty-six thousand, four hundred twenty-six".