65661898 has 4 divisors (see below), whose sum is σ = 98492850. Its totient is φ = 32830948.

The previous prime is 65661863. The next prime is 65661899. The reversal of 65661898 is 89816656.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 65561409 + 100489 = 8097^2 + 317^2 .

It is a super-2 number, since 2×65661898² = 8622969697924808, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (65661899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16415473 + ... + 16415476.

Almost surely, 2^65661898 is an apocalyptic number.

65661898 is a deficient number, since it is larger than the sum of its proper divisors (32830952).

65661898 is a wasteful number, since it uses less digits than its factorization.

65661898 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32830951.

The product of its digits is 622080, while the sum is 49.

The square root of 65661898 is about 8103.2029469834. The cubic root of 65661898 is about 403.4327439013.

It can be divided in two parts, 6566 and 1898, that added together give a square (8464 = 92²).

The spelling of 65661898 in words is "sixty-five million, six hundred sixty-one thousand, eight hundred ninety-eight".