660426421 has 8 divisors (see below), whose sum is σ = 706065984. Its totient is φ = 615541440.

The previous prime is 660426419. The next prime is 660426427. The reversal of 660426421 is 124624066.

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

It is not a de Polignac number, because 660426421 - 2¹ = 660426419 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660426427) 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, 186835 + ... + 190336.

It is an arithmetic number, because the mean of its divisors is an integer number (88258248).

Almost surely, 2^660426421 is an apocalyptic number.

It is an amenable number.

660426421 is a deficient number, since it is larger than the sum of its proper divisors (45639563).

660426421 is a wasteful number, since it uses less digits than its factorization.

660426421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 377291.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 660426421 is about 25698.7630247061. The cubic root of 660426421 is about 870.8462374275.

The spelling of 660426421 in words is "six hundred sixty million, four hundred twenty-six thousand, four hundred twenty-one".