42099961 has 2 divisors, whose sum is σ = 42099962. Its totient is φ = 42099960.

The previous prime is 42099949. The next prime is 42099971. The reversal of 42099961 is 16999024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 41990400 + 109561 = 6480^2 + 331^2 .

It is a cyclic number.

It is not a de Polignac number, because 42099961 - 2¹⁷ = 41968889 is a prime.

It is not a weakly prime, because it can be changed into another prime (42099901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21049980 + 21049981.

It is an arithmetic number, because the mean of its divisors is an integer number (21049981).

Almost surely, 2^42099961 is an apocalyptic number.

It is an amenable number.

42099961 is a deficient number, since it is larger than the sum of its proper divisors (1).

42099961 is an equidigital number, since it uses as much as digits as its factorization.

42099961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 40.

The square root of 42099961 is about 6488.4482736630. The cubic root of 42099961 is about 347.8782135389.

The spelling of 42099961 in words is "forty-two million, ninety-nine thousand, nine hundred sixty-one".