42198661 has 2 divisors, whose sum is σ = 42198662. Its totient is φ = 42198660.

The previous prime is 42198643. The next prime is 42198691. The reversal of 42198661 is 16689124.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40832100 + 1366561 = 6390^2 + 1169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42198661 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42198661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42198691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21099330 + 21099331.

It is an arithmetic number, because the mean of its divisors is an integer number (21099331).

Almost surely, 2^42198661 is an apocalyptic number.

It is an amenable number.

42198661 is a deficient number, since it is larger than the sum of its proper divisors (1).

42198661 is an equidigital number, since it uses as much as digits as its factorization.

42198661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 42198661 is about 6496.0496457463. The cubic root of 42198661 is about 348.1498589389.

It can be divided in two parts, 4219 and 8661, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 42198661 in words is "forty-two million, one hundred ninety-eight thousand, six hundred sixty-one".