42521645378 has 4 divisors (see below), whose sum is σ = 63782468070. Its totient is φ = 21260822688.

The previous prime is 42521645371. The next prime is 42521645381. The reversal of 42521645378 is 87354612524.

42521645378 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 29259128809 + 13262516569 = 171053^2 + 115163^2 .

It is not an unprimeable number, because it can be changed into a prime (42521645371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10630411343 + ... + 10630411346.

Almost surely, 2^42521645378 is an apocalyptic number.

42521645378 is a deficient number, since it is larger than the sum of its proper divisors (21260822692).

42521645378 is a wasteful number, since it uses less digits than its factorization.

42521645378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21260822691.

The product of its digits is 1612800, while the sum is 47.

The spelling of 42521645378 in words is "forty-two billion, five hundred twenty-one million, six hundred forty-five thousand, three hundred seventy-eight".