42758921 has 2 divisors, whose sum is σ = 42758922. Its totient is φ = 42758920.

The previous prime is 42758917. The next prime is 42758929. The reversal of 42758921 is 12985724.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42758521 + 400 = 6539^2 + 20^2 .

It is a cyclic number.

It is not a de Polignac number, because 42758921 - 2² = 42758917 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42758929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21379460 + 21379461.

It is an arithmetic number, because the mean of its divisors is an integer number (21379461).

Almost surely, 2^42758921 is an apocalyptic number.

It is an amenable number.

42758921 is a deficient number, since it is larger than the sum of its proper divisors (1).

42758921 is an equidigital number, since it uses as much as digits as its factorization.

42758921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 38.

The square root of 42758921 is about 6539.0305856449. The cubic root of 42758921 is about 349.6838532937.

It can be divided in two parts, 4 and 2758921, that multiplied together give a square (11035684 = 3322²).

The spelling of 42758921 in words is "forty-two million, seven hundred fifty-eight thousand, nine hundred twenty-one".