660751421 has 8 divisors (see below), whose sum is σ = 721224000. Its totient is φ = 600346240.

The previous prime is 660751417. The next prime is 660751423. The reversal of 660751421 is 124157066.

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

It is a cyclic number.

It is not a de Polignac number, because 660751421 - 2² = 660751417 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 (660751423) 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, 4880 + ... + 36678.

It is an arithmetic number, because the mean of its divisors is an integer number (90153000).

Almost surely, 2^660751421 is an apocalyptic number.

It is an amenable number.

660751421 is a deficient number, since it is larger than the sum of its proper divisors (60472579).

660751421 is a wasteful number, since it uses less digits than its factorization.

660751421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33699.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 660751421 is about 25705.0855085137. The cubic root of 660751421 is about 870.9890636403.

The spelling of 660751421 in words is "six hundred sixty million, seven hundred fifty-one thousand, four hundred twenty-one".