661426 has 8 divisors (see below), whose sum is σ = 1015344. Its totient is φ = 322980.

The previous prime is 661421. The next prime is 661439. The reversal of 661426 is 624166.

It is a happy number.

661426 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a self number, because there is not a number n which added to its sum of digits gives 661426.

It is not an unprimeable number, because it can be changed into a prime (661421) 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, 3760 + ... + 3931.

It is an arithmetic number, because the mean of its divisors is an integer number (126918).

2⁶⁶¹⁴²⁶ is an apocalyptic number.

661426 is a deficient number, since it is larger than the sum of its proper divisors (353918).

661426 is a wasteful number, since it uses less digits than its factorization.

661426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7736.

The product of its digits is 1728, while the sum is 25.

The square root of 661426 is about 813.2810092459. The cubic root of 661426 is about 87.1285368260.

The spelling of 661426 in words is "six hundred sixty-one thousand, four hundred twenty-six".