66051989 has 4 divisors (see below), whose sum is σ = 66078240. Its totient is φ = 66025740.

The previous prime is 66051983. The next prime is 66052009. The reversal of 66051989 is 98915066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66051989 - 2¹² = 66047893 is a prime.

It is a super-2 number, since 2×66051989² = 8725730501712242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66051983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8897 + ... + 14534.

It is an arithmetic number, because the mean of its divisors is an integer number (16519560).

Almost surely, 2^66051989 is an apocalyptic number.

It is an amenable number.

66051989 is a deficient number, since it is larger than the sum of its proper divisors (26251).

66051989 is a wasteful number, since it uses less digits than its factorization.

66051989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26250.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 66051989 is about 8127.2374765353. The cubic root of 66051989 is about 404.2300853377.

The spelling of 66051989 in words is "sixty-six million, fifty-one thousand, nine hundred eighty-nine".