669636240 has 160 divisors (see below), whose sum is σ = 2555003136. Its totient is φ = 141281280.

The previous prime is 669636229. The next prime is 669636241. The reversal of 669636240 is 42636966.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 669636192 and 669636201.

It is not an unprimeable number, because it can be changed into a prime (669636241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6510 + ... + 37170.

Almost surely, 2^669636240 is an apocalyptic number.

669636240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669636240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1277501568).

669636240 is an abundant number, since it is smaller than the sum of its proper divisors (1885366896).

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

669636240 is a wasteful number, since it uses less digits than its factorization.

669636240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30697 (or 30691 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 42.

The square root of 669636240 is about 25877.3306196756. The cubic root of 669636240 is about 874.8756242264.

The spelling of 669636240 in words is "six hundred sixty-nine million, six hundred thirty-six thousand, two hundred forty".