42979840 has 80 divisors (see below), whose sum is σ = 104689728. Its totient is φ = 16920576.

The previous prime is 42979837. The next prime is 42979861. The reversal of 42979840 is 4897924.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 263599 + ... + 263761.

Almost surely, 2^42979840 is an apocalyptic number.

42979840 is a gapful number since it is divisible by the number (40) 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 42979840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52344864).

42979840 is an abundant number, since it is smaller than the sum of its proper divisors (61709888).

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

42979840 is a wasteful number, since it uses less digits than its factorization.

42979840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 43.

The square root of 42979840 is about 6555.9011584983. The cubic root of 42979840 is about 350.2850467011.

The spelling of 42979840 in words is "forty-two million, nine hundred seventy-nine thousand, eight hundred forty".