660426261 has 8 divisors (see below), whose sum is σ = 960620064. Its totient is φ = 400258320.

The previous prime is 660426257. The next prime is 660426271. The reversal of 660426261 is 162624066.

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

It is not a de Polignac number, because 660426261 - 2² = 660426257 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 20012917 = 660426261 / (6 + 6 + 0 + 4 + 2 + 6 + 2 + 6 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660426211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10006426 + ... + 10006491.

It is an arithmetic number, because the mean of its divisors is an integer number (120077508).

Almost surely, 2^660426261 is an apocalyptic number.

It is an amenable number.

660426261 is a deficient number, since it is larger than the sum of its proper divisors (300193803).

660426261 is a wasteful number, since it uses less digits than its factorization.

660426261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20012931.

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 660426261 is about 25698.7599117156. The cubic root of 660426261 is about 870.8461671015.

The spelling of 660426261 in words is "six hundred sixty million, four hundred twenty-six thousand, two hundred sixty-one".