66561442 has 8 divisors (see below), whose sum is σ = 99894096. Its totient is φ = 33263412.

The previous prime is 66561437. The next prime is 66561461. The reversal of 66561442 is 24416566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×66561442² = 8860851122238728, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66561398 and 66561407.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3148 + ... + 11959.

It is an arithmetic number, because the mean of its divisors is an integer number (12486762).

Almost surely, 2^66561442 is an apocalyptic number.

66561442 is a deficient number, since it is larger than the sum of its proper divisors (33332654).

66561442 is a wasteful number, since it uses less digits than its factorization.

66561442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17312.

The product of its digits is 34560, while the sum is 34.

The square root of 66561442 is about 8158.5195961032. The cubic root of 66561442 is about 405.2666881413.

The spelling of 66561442 in words is "sixty-six million, five hundred sixty-one thousand, four hundred forty-two".