42291781 has 16 divisors (see below), whose sum is σ = 50544640. Its totient is φ = 34622640.

The previous prime is 42291761. The next prime is 42291791. The reversal of 42291781 is 18719224.

42291781 = 329² + 330² + ... + 545².

It is a cyclic number.

It is not a de Polignac number, because 42291781 - 2⁵ = 42291749 is a prime.

It is a super-2 number, since 2×42291781² = 3577189480303922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42291751) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15910 + ... + 18376.

It is an arithmetic number, because the mean of its divisors is an integer number (3159040).

Almost surely, 2^42291781 is an apocalyptic number.

It is an amenable number.

42291781 is a deficient number, since it is larger than the sum of its proper divisors (8252859).

42291781 is a wasteful number, since it uses less digits than its factorization.

42291781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2584.

The product of its digits is 8064, while the sum is 34.

The square root of 42291781 is about 6503.2131289079. The cubic root of 42291781 is about 348.4057588211.

The spelling of 42291781 in words is "forty-two million, two hundred ninety-one thousand, seven hundred eighty-one".