66512021125 has 48 divisors (see below), whose sum is σ = 91333110960. Its totient is φ = 48322560000.

The previous prime is 66512021119. The next prime is 66512021131. The reversal of 66512021125 is 52112021566.

It is an interprime number because it is at equal distance from previous prime (66512021119) and next prime (66512021131).

It can be written as a sum of positive squares in 8 ways, for example, as 62471003364 + 4041017761 = 249942^2 + 63569^2 .

It is not a de Polignac number, because 66512021125 - 2³ = 66512021117 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21309565 + ... + 21312685.

It is an arithmetic number, because the mean of its divisors is an integer number (1902773145).

Almost surely, 2^66512021125 is an apocalyptic number.

It is an amenable number.

66512021125 is a deficient number, since it is larger than the sum of its proper divisors (24821089835).

66512021125 is a wasteful number, since it uses less digits than its factorization.

66512021125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4567 (or 4546 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 31.

It can be divided in two parts, 6651 and 2021125, that added together give a square (2027776 = 1424²).

The spelling of 66512021125 in words is "sixty-six billion, five hundred twelve million, twenty-one thousand, one hundred twenty-five".