42015681 has 6 divisors (see below), whose sum is σ = 60689330. Its totient is φ = 28010448.

The previous prime is 42015671. The next prime is 42015691. The reversal of 42015681 is 18651024.

It is an interprime number because it is at equal distance from previous prime (42015671) and next prime (42015691).

It can be written as a sum of positive squares in only one way, i.e., 41990400 + 25281 = 6480^2 + 159^2 .

It is not a de Polignac number, because 42015681 - 2²³ = 33627073 is a prime.

It is a super-2 number, since 2×42015681² = 3530634899787522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42015671) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2334196 + ... + 2334213.

Almost surely, 2^42015681 is an apocalyptic number.

It is an amenable number.

42015681 is a deficient number, since it is larger than the sum of its proper divisors (18673649).

42015681 is a wasteful number, since it uses less digits than its factorization.

42015681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4668415 (or 4668412 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 42015681 is about 6481.9504009210. The cubic root of 42015681 is about 347.6459190852.

The spelling of 42015681 in words is "forty-two million, fifteen thousand, six hundred eighty-one".