66949970820 has 24 divisors (see below), whose sum is σ = 187459918464. Its totient is φ = 17853325536.

The previous prime is 66949970819. The next prime is 66949970821. The reversal of 66949970820 is 2807994966.

It is an interprime number because it is at equal distance from previous prime (66949970819) and next prime (66949970821).

It is a Harshad number since it is a multiple of its sum of digits (60), and also a Moran number because the ratio is a prime number: 1115832847 = 66949970820 / (6 + 6 + 9 + 4 + 9 + 9 + 7 + 0 + 8 + 2 + 0).

It is not an unprimeable number, because it can be changed into a prime (66949970821) 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, 557916364 + ... + 557916483.

It is an arithmetic number, because the mean of its divisors is an integer number (7810829936).

Almost surely, 2^66949970820 is an apocalyptic number.

66949970820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66949970820 is an abundant number, since it is smaller than the sum of its proper divisors (120509947644).

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

66949970820 is a wasteful number, since it uses less digits than its factorization.

66949970820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1115832859 (or 1115832857 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 60.

The spelling of 66949970820 in words is "sixty-six billion, nine hundred forty-nine million, nine hundred seventy thousand, eight hundred twenty".