66666490 has 16 divisors (see below), whose sum is σ = 130908960. Its totient is φ = 24242320.

The previous prime is 66666487. The next prime is 66666493. The reversal of 66666490 is 9466666.

It is an interprime number because it is at equal distance from previous prime (66666487) and next prime (66666493).

It is not an unprimeable number, because it can be changed into a prime (66666493) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 302920 + ... + 303139.

It is an arithmetic number, because the mean of its divisors is an integer number (8181810).

Almost surely, 2^66666490 is an apocalyptic number.

66666490 is a deficient number, since it is larger than the sum of its proper divisors (64242470).

66666490 is a wasteful number, since it uses less digits than its factorization.

66666490 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 606077.

The product of its (nonzero) digits is 279936, while the sum is 43.

The square root of 66666490 is about 8164.9549906904. The cubic root of 66666490 is about 405.4797748638.

The spelling of 66666490 in words is "sixty-six million, six hundred sixty-six thousand, four hundred ninety".