42636491 has 2 divisors, whose sum is σ = 42636492. Its totient is φ = 42636490.

The previous prime is 42636487. The next prime is 42636533. The reversal of 42636491 is 19463624.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42636491 - 2² = 42636487 is a prime.

It is not a weakly prime, because it can be changed into another prime (42636421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21318245 + 21318246.

It is an arithmetic number, because the mean of its divisors is an integer number (21318246).

Almost surely, 2^42636491 is an apocalyptic number.

42636491 is a deficient number, since it is larger than the sum of its proper divisors (1).

42636491 is an equidigital number, since it uses as much as digits as its factorization.

42636491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 35.

The square root of 42636491 is about 6529.6623955607. The cubic root of 42636491 is about 349.3497887387.

The spelling of 42636491 in words is "forty-two million, six hundred thirty-six thousand, four hundred ninety-one".