42878516315681 has 2 divisors, whose sum is σ = 42878516315682. Its totient is φ = 42878516315680.

The previous prime is 42878516315611. The next prime is 42878516315731. The reversal of 42878516315681 is 18651361587824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42298321808656 + 580194507025 = 6503716^2 + 761705^2 .

It is a cyclic number.

It is not a de Polignac number, because 42878516315681 - 2¹⁸ = 42878516053537 is a prime.

It is a super-2 number, since 2×42878516315681² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (42878516315611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21439258157840 + 21439258157841.

It is an arithmetic number, because the mean of its divisors is an integer number (21439258157841).

Almost surely, 2^{42878516315681} is an apocalyptic number.

It is an amenable number.

42878516315681 is a deficient number, since it is larger than the sum of its proper divisors (1).

42878516315681 is an equidigital number, since it uses as much as digits as its factorization.

42878516315681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 77414400, while the sum is 65.

The spelling of 42878516315681 in words is "forty-two trillion, eight hundred seventy-eight billion, five hundred sixteen million, three hundred fifteen thousand, six hundred eighty-one".