646213620 has 96 divisors (see below), whose sum is σ = 1953044352. Its totient is φ = 158704128.

The previous prime is 646213619. The next prime is 646213627. The reversal of 646213620 is 26312646.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646213627) 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, 532134 + ... + 533346.

It is an arithmetic number, because the mean of its divisors is an integer number (20344212).

Almost surely, 2^646213620 is an apocalyptic number.

646213620 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 646213620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (976522176).

646213620 is an abundant number, since it is smaller than the sum of its proper divisors (1306830732).

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

646213620 is a wasteful number, since it uses less digits than its factorization.

646213620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1921 (or 1919 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 646213620 is about 25420.7320901661. The cubic root of 646213620 is about 864.5538233788.

The spelling of 646213620 in words is "six hundred forty-six million, two hundred thirteen thousand, six hundred twenty".