42390840 has 64 divisors (see below), whose sum is σ = 132710400. Its totient is φ = 10812032.

The previous prime is 42390827. The next prime is 42390841. The reversal of 42390840 is 4809324.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 42390798 and 42390807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42390841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4920 + ... + 10439.

It is an arithmetic number, because the mean of its divisors is an integer number (2073600).

Almost surely, 2^42390840 is an apocalyptic number.

42390840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

42390840 is an abundant number, since it is smaller than the sum of its proper divisors (90319560).

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

42390840 is a wasteful number, since it uses less digits than its factorization.

42390840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15396 (or 15392 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 42390840 is about 6510.8248325385. The cubic root of 42390840 is about 348.6775674653.

The spelling of 42390840 in words is "forty-two million, three hundred ninety thousand, eight hundred forty".