42220081 has 2 divisors, whose sum is σ = 42220082. Its totient is φ = 42220080.

The previous prime is 42219979. The next prime is 42220091. The reversal of 42220081 is 18002224.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28090000 + 14130081 = 5300^2 + 3759^2 .

It is a cyclic number.

It is not a de Polignac number, because 42220081 - 2¹³ = 42211889 is a prime.

It is a super-2 number, since 2×42220081² = 3565070479293122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (42220091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21110040 + 21110041.

It is an arithmetic number, because the mean of its divisors is an integer number (21110041).

Almost surely, 2^42220081 is an apocalyptic number.

It is an amenable number.

42220081 is a deficient number, since it is larger than the sum of its proper divisors (1).

42220081 is an equidigital number, since it uses as much as digits as its factorization.

42220081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 42220081 is about 6497.6981308768. The cubic root of 42220081 is about 348.2087558199.

It can be divided in two parts, 422 and 20081, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 42220081 in words is "forty-two million, two hundred twenty thousand, eighty-one".