1961664 has 56 divisors (see below), whose sum is σ = 5504688. Its totient is φ = 614400.

The previous prime is 1961657. The next prime is 1961669. The reversal of 1961664 is 4661691.

It is not an unprimeable number, because it can be changed into a prime (1961669) 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, 2964 + ... + 3564.

It is an arithmetic number, because the mean of its divisors is an integer number (98298).

2^1961664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1961664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2752344).

1961664 is an abundant number, since it is smaller than the sum of its proper divisors (3543024).

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

1961664 is a wasteful number, since it uses less digits than its factorization.

1961664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633 (or 623 counting only the distinct ones).

The product of its digits is 7776, while the sum is 33.

The square root of 1961664 is about 1400.5941596337. The cubic root of 1961664 is about 125.1819005026.

The spelling of 1961664 in words is "one million, nine hundred sixty-one thousand, six hundred sixty-four".