42661890 has 80 divisors (see below), whose sum is σ = 118483200. Its totient is φ = 11003040.

The previous prime is 42661889. The next prime is 42661903. The reversal of 42661890 is 9816624.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 24261 + ... + 25959.

It is an arithmetic number, because the mean of its divisors is an integer number (1481040).

Almost surely, 2^42661890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42661890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59241600).

42661890 is an abundant number, since it is smaller than the sum of its proper divisors (75821310).

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

42661890 is a wasteful number, since it uses less digits than its factorization.

42661890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1749 (or 1740 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 42661890 is about 6531.6069998125. The cubic root of 42661890 is about 349.4191453995.

The spelling of 42661890 in words is "forty-two million, six hundred sixty-one thousand, eight hundred ninety".