66921500 has 24 divisors (see below), whose sum is σ = 146157648. Its totient is φ = 26768400.

The previous prime is 66921497. The next prime is 66921527. The reversal of 66921500 is 512966.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66422 + ... + 67421.

It is an arithmetic number, because the mean of its divisors is an integer number (6089902).

Almost surely, 2^66921500 is an apocalyptic number.

It is an amenable number.

66921500 is an abundant number, since it is smaller than the sum of its proper divisors (79236148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66921500 is a wasteful number, since it uses less digits than its factorization.

66921500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133862 (or 133850 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 66921500 is about 8180.5562158083. The cubic root of 66921500 is about 405.9961254049.

It can be divided in two parts, 6692 and 1500, that added together give a 13-th power (8192 = 2¹³).

The spelling of 66921500 in words is "sixty-six million, nine hundred twenty-one thousand, five hundred".