661374 has 48 divisors (see below), whose sum is σ = 1703520. Its totient is φ = 181440.

The previous prime is 661373. The next prime is 661393. The reversal of 661374 is 473166.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661373) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3564 + ... + 3744.

It is an arithmetic number, because the mean of its divisors is an integer number (35490).

2⁶⁶¹³⁷⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661374, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851760).

661374 is an abundant number, since it is smaller than the sum of its proper divisors (1042146).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661374 is a wasteful number, since it uses less digits than its factorization.

661374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225 (or 222 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 661374 is about 813.2490393477. The cubic root of 661374 is about 87.1262534753.

It can be divided in two parts, 661 and 374, that added together give a triangular number (1035 = T₄₅).

The spelling of 661374 in words is "six hundred sixty-one thousand, three hundred seventy-four".