661402 has 24 divisors (see below), whose sum is σ = 1225044. Its totient is φ = 266112.

The previous prime is 661393. The next prime is 661417. The reversal of 661402 is 204166.

661402 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 625681 + 35721 = 791^2 + 189^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 661402.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1468 + ... + 1864.

2⁶⁶¹⁴⁰² is an apocalyptic number.

661402 is a deficient number, since it is larger than the sum of its proper divisors (563642).

661402 is a wasteful number, since it uses less digits than its factorization.

661402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 661402 is about 813.2662540644. The cubic root of 661402 is about 87.1274829867.

Adding to 661402 its reverse (204166), we get a palindrome (865568).

The spelling of 661402 in words is "six hundred sixty-one thousand, four hundred two".