42156840 has 128 divisors (see below), whose sum is σ = 139708800. Its totient is φ = 10091520.

The previous prime is 42156817. The next prime is 42156859. The reversal of 42156840 is 4865124.

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 = 42156798 and 42156807.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 143734 + ... + 144026.

It is an arithmetic number, because the mean of its divisors is an integer number (1091475).

Almost surely, 2^42156840 is an apocalyptic number.

42156840 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 42156840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69854400).

42156840 is an abundant number, since it is smaller than the sum of its proper divisors (97551960).

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

42156840 is a wasteful number, since it uses less digits than its factorization.

42156840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 42156840 is about 6492.8298915034. The cubic root of 42156840 is about 348.0348095712.

The spelling of 42156840 in words is "forty-two million, one hundred fifty-six thousand, eight hundred forty".