669249040 has 20 divisors (see below), whose sum is σ = 1556004204. Its totient is φ = 267699584.

The previous prime is 669249023. The next prime is 669249041. The reversal of 669249040 is 40942966.

It can be written as a sum of positive squares in 2 ways, for example, as 458302464 + 210946576 = 21408^2 + 14524^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 669248984 and 669249002.

It is not an unprimeable number, because it can be changed into a prime (669249041) 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, 4182727 + ... + 4182886.

Almost surely, 2^669249040 is an apocalyptic number.

It is an amenable number.

669249040 is an abundant number, since it is smaller than the sum of its proper divisors (886755164).

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

669249040 is a wasteful number, since it uses less digits than its factorization.

669249040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8365626 (or 8365620 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 40.

The square root of 669249040 is about 25869.8480861407. The cubic root of 669249040 is about 874.7069669097.

The spelling of 669249040 in words is "six hundred sixty-nine million, two hundred forty-nine thousand, forty".