642449220 has 96 divisors (see below), whose sum is σ = 2061550848. Its totient is φ = 146437632.

The previous prime is 642449219. The next prime is 642449221. The reversal of 642449220 is 22944246.

It is an interprime number because it is at equal distance from previous prime (642449219) and next prime (642449221).

It is not an unprimeable number, because it can be changed into a prime (642449221) 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, 164814 + ... + 168666.

It is an arithmetic number, because the mean of its divisors is an integer number (21474488).

Almost surely, 2^642449220 is an apocalyptic number.

642449220 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 642449220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1030775424).

642449220 is an abundant number, since it is smaller than the sum of its proper divisors (1419101628).

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

642449220 is a wasteful number, since it uses less digits than its factorization.

642449220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4269 (or 4267 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 642449220 is about 25346.5820180947. The cubic root of 642449220 is about 862.8717859461.

The spelling of 642449220 in words is "six hundred forty-two million, four hundred forty-nine thousand, two hundred twenty".