1640468 has 6 divisors (see below), whose sum is σ = 2870826. Its totient is φ = 820232.

The previous prime is 1640467. The next prime is 1640497. The reversal of 1640468 is 8640461.

It can be written as a sum of positive squares in only one way, i.e., 1044484 + 595984 = 1022^2 + 772^2 .

It is a super-2 number, since 2×1640468² = 5382270518048, which contains 22 as substring.

It is an Ulam number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 1640468.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1640461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205055 + ... + 205062.

It is an arithmetic number, because the mean of its divisors is an integer number (478471).

2^1640468 is an apocalyptic number.

It is an amenable number.

1640468 is a deficient number, since it is larger than the sum of its proper divisors (1230358).

1640468 is a wasteful number, since it uses less digits than its factorization.

1640468 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410121 (or 410119 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 1640468 is about 1280.8075577541. The cubic root of 1640468 is about 117.9385872142.

The spelling of 1640468 in words is "one million, six hundred forty thousand, four hundred sixty-eight".