42007778 has 6 divisors (see below), whose sum is σ = 63025419. Its totient is φ = 20999306.

The previous prime is 42007753. The next prime is 42007781. The reversal of 42007778 is 87770024.

It can be written as a sum of positive squares in only one way, i.e., 21003889 + 21003889 = 4583^2 + 4583^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=4583.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 6875 + ... + 11457.

Almost surely, 2^42007778 is an apocalyptic number.

42007778 is a deficient number, since it is larger than the sum of its proper divisors (21017641).

42007778 is an frugal number, since it uses more digits than its factorization.

42007778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9168 (or 4585 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 35.

The square root of 42007778 is about 6481.3407563559. The cubic root of 42007778 is about 347.6241207319.

The spelling of 42007778 in words is "forty-two million, seven thousand, seven hundred seventy-eight".