1669396840 has 16 divisors (see below), whose sum is σ = 3756142980. Its totient is φ = 667758720.

The previous prime is 1669396837. The next prime is 1669396843. The reversal of 1669396840 is 486939661.

It is an interprime number because it is at equal distance from previous prime (1669396837) and next prime (1669396843).

It can be written as a sum of positive squares in 2 ways, for example, as 1658281284 + 11115556 = 40722^2 + 3334^2 .

It is not an unprimeable number, because it can be changed into a prime (1669396843) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20867421 + ... + 20867500.

Almost surely, 2^1669396840 is an apocalyptic number.

1669396840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1669396840 is an abundant number, since it is smaller than the sum of its proper divisors (2086746140).

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

1669396840 is a wasteful number, since it uses less digits than its factorization.

1669396840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41734932 (or 41734928 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 52.

The square root of 1669396840 is about 40858.2530218804. The cubic root of 1669396840 is about 1186.2781440009.

The spelling of 1669396840 in words is "one billion, six hundred sixty-nine million, three hundred ninety-six thousand, eight hundred forty".