66761625428 has 6 divisors (see below), whose sum is σ = 116832844506. Its totient is φ = 33380812712.

The previous prime is 66761625419. The next prime is 66761625449. The reversal of 66761625428 is 82452616766.

It can be written as a sum of positive squares in only one way, i.e., 52289054224 + 14472571204 = 228668^2 + 120302^2 .

It is a super-2 number, since 2×66761625428² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66761625428.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8345203175 + ... + 8345203182.

It is an arithmetic number, because the mean of its divisors is an integer number (19472140751).

Almost surely, 2^66761625428 is an apocalyptic number.

It is an amenable number.

66761625428 is a deficient number, since it is larger than the sum of its proper divisors (50071219078).

66761625428 is a wasteful number, since it uses less digits than its factorization.

66761625428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16690406361 (or 16690406359 counting only the distinct ones).

The product of its digits is 5806080, while the sum is 53.

The spelling of 66761625428 in words is "sixty-six billion, seven hundred sixty-one million, six hundred twenty-five thousand, four hundred twenty-eight".