42987780 has 96 divisors (see below), whose sum is σ = 145918080. Its totient is φ = 10419840.

The previous prime is 42987779. The next prime is 42987787. The reversal of 42987780 is 8778924.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (42987787) 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, 2322 + ... + 9558.

It is an arithmetic number, because the mean of its divisors is an integer number (1519980).

Almost surely, 2^42987780 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 42987780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72959040).

42987780 is an abundant number, since it is smaller than the sum of its proper divisors (102930300).

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

42987780 is a wasteful number, since it uses less digits than its factorization.

42987780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7266 (or 7258 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The square root of 42987780 is about 6556.5066918291. The cubic root of 42987780 is about 350.3066156663.

Subtracting from 42987780 its reverse (8778924), we obtain a triangular number (34208856 = T₈₂₇₁).

It can be divided in two parts, 429 and 87780, that added together give a square (88209 = 297²).

The spelling of 42987780 in words is "forty-two million, nine hundred eighty-seven thousand, seven hundred eighty".