661602643 has 16 divisors (see below), whose sum is σ = 723520000. Its totient is φ = 601305120.

The previous prime is 661602619. The next prime is 661602647. The reversal of 661602643 is 346206166.

It is not a de Polignac number, because 661602643 - 2⁵ = 661602611 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661602599 and 661602608.

It is not an unprimeable number, because it can be changed into a prime (661602647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 511828 + ... + 513118.

It is an arithmetic number, because the mean of its divisors is an integer number (45220000).

Almost surely, 2^661602643 is an apocalyptic number.

661602643 is a deficient number, since it is larger than the sum of its proper divisors (61917357).

661602643 is a wasteful number, since it uses less digits than its factorization.

661602643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1882.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 661602643 is about 25721.6376422653. The cubic root of 661602643 is about 871.3629243096.

The spelling of 661602643 in words is "six hundred sixty-one million, six hundred two thousand, six hundred forty-three".