42640506 has 20 divisors (see below), whose sum is σ = 95546682. Its totient is φ = 14213448.

The previous prime is 42640489. The next prime is 42640511. The reversal of 42640506 is 60504624.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 32661225 + 9979281 = 5715^2 + 3159^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 42640506.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 131445 + ... + 131768.

Almost surely, 2^42640506 is an apocalyptic number.

42640506 is an abundant number, since it is smaller than the sum of its proper divisors (52906176).

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

42640506 is a wasteful number, since it uses less digits than its factorization.

42640506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263227 (or 263218 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 42640506 is about 6529.9698314770. The cubic root of 42640506 is about 349.3607542704.

The spelling of 42640506 in words is "forty-two million, six hundred forty thousand, five hundred six".