66537761 has 4 divisors (see below), whose sum is σ = 66584112. Its totient is φ = 66491412.

The previous prime is 66537719. The next prime is 66537769. The reversal of 66537761 is 16773566.

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 66537761 - 2¹⁰ = 66536737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66537769) 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, 20951 + ... + 23916.

It is an arithmetic number, because the mean of its divisors is an integer number (16646028).

Almost surely, 2^66537761 is an apocalyptic number.

It is an amenable number.

66537761 is a deficient number, since it is larger than the sum of its proper divisors (46351).

66537761 is a wasteful number, since it uses less digits than its factorization.

66537761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46350.

The product of its digits is 158760, while the sum is 41.

The square root of 66537761 is about 8157.0681620298. The cubic root of 66537761 is about 405.2186209795.

The spelling of 66537761 in words is "sixty-six million, five hundred thirty-seven thousand, seven hundred sixty-one".