1640402 has 4 divisors (see below), whose sum is σ = 2460606. Its totient is φ = 820200.

The previous prime is 1640399. The next prime is 1640423. The reversal of 1640402 is 2040461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1002001 + 638401 = 1001^2 + 799^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410099 + ... + 410102.

2^1640402 is an apocalyptic number.

1640402 is a deficient number, since it is larger than the sum of its proper divisors (820204).

1640402 is an equidigital number, since it uses as much as digits as its factorization.

1640402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820203.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 1640402 is about 1280.7817925002. The cubic root of 1640402 is about 117.9370055413.

Adding to 1640402 its reverse (2040461), we get a palindrome (3680863).

The spelling of 1640402 in words is "one million, six hundred forty thousand, four hundred two".