66620157409 has 8 divisors (see below), whose sum is σ = 74864123712. Its totient is φ = 58821810960.

The previous prime is 66620157389. The next prime is 66620157451. The reversal of 66620157409 is 90475102666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66620157409 - 2⁷ = 66620157281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66620157479) 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, 111404647 + ... + 111405244.

It is an arithmetic number, because the mean of its divisors is an integer number (9358015464).

Almost surely, 2^66620157409 is an apocalyptic number.

It is an amenable number.

66620157409 is a deficient number, since it is larger than the sum of its proper divisors (8243966303).

66620157409 is a wasteful number, since it uses less digits than its factorization.

66620157409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222809927.

The product of its (nonzero) digits is 544320, while the sum is 46.

It can be divided in two parts, 666 and 20157409, that added together give a triangular number (20158075 = T₆₃₄₉).

The spelling of 66620157409 in words is "sixty-six billion, six hundred twenty million, one hundred fifty-seven thousand, four hundred nine".