623640990 has 128 divisors (see below), whose sum is σ = 1814400000. Its totient is φ = 134009856.

The previous prime is 623640989. The next prime is 623640991. The reversal of 623640990 is 99046326.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (623640989) and next prime (623640991).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623640991) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 593986 + ... + 595034.

It is an arithmetic number, because the mean of its divisors is an integer number (14175000).

Almost surely, 2^623640990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 623640990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907200000).

623640990 is an abundant number, since it is smaller than the sum of its proper divisors (1190759010).

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

623640990 is a wasteful number, since it uses less digits than its factorization.

623640990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1234.

The product of its (nonzero) digits is 69984, while the sum is 39.

The square root of 623640990 is about 24972.8050086489. The cubic root of 623640990 is about 854.3678237902.

The spelling of 623640990 in words is "six hundred twenty-three million, six hundred forty thousand, nine hundred ninety".