1660404621 has 8 divisors (see below), whose sum is σ = 2219287360. Its totient is φ = 1104229152.

The previous prime is 1660404611. The next prime is 1660404631. The reversal of 1660404621 is 1264040661.

It is an interprime number because it is at equal distance from previous prime (1660404611) and next prime (1660404631).

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

It is not a de Polignac number, because 1660404621 - 2¹¹ = 1660402573 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 (1660404601) 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, 675385 + ... + 677838.

It is an arithmetic number, because the mean of its divisors is an integer number (277410920).

Almost surely, 2^1660404621 is an apocalyptic number.

It is an amenable number.

1660404621 is a deficient number, since it is larger than the sum of its proper divisors (558882739).

1660404621 is a wasteful number, since it uses less digits than its factorization.

1660404621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1353635.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 1660404621 is about 40748.0627883093. The cubic root of 1660404621 is about 1184.1443426885.

The spelling of 1660404621 in words is "one billion, six hundred sixty million, four hundred four thousand, six hundred twenty-one".