66506474 has 4 divisors (see below), whose sum is σ = 99759714. Its totient is φ = 33253236.

The previous prime is 66506443. The next prime is 66506477. The reversal of 66506474 is 47460566.

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., 66308449 + 198025 = 8143^2 + 445^2 .

It is a super-2 number, since 2×66506474² = 8846222167825352, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66506477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16626617 + ... + 16626620.

Almost surely, 2^66506474 is an apocalyptic number.

66506474 is a deficient number, since it is larger than the sum of its proper divisors (33253240).

66506474 is a wasteful number, since it uses less digits than its factorization.

66506474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33253239.

The product of its (nonzero) digits is 120960, while the sum is 38.

The square root of 66506474 is about 8155.1501518979. The cubic root of 66506474 is about 405.1550978388.

The spelling of 66506474 in words is "sixty-six million, five hundred six thousand, four hundred seventy-four".