66061002157 has 4 divisors (see below), whose sum is σ = 66318049116. Its totient is φ = 65803955200.

The previous prime is 66061002113. The next prime is 66061002191. The reversal of 66061002157 is 75120016066.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38939523561 + 27121478596 = 197331^2 + 164686^2 .

It is a cyclic number.

It is not a de Polignac number, because 66061002157 - 2³¹ = 63913518509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66061002257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128523094 + ... + 128523607.

It is an arithmetic number, because the mean of its divisors is an integer number (16579512279).

Almost surely, 2^66061002157 is an apocalyptic number.

It is an amenable number.

66061002157 is a deficient number, since it is larger than the sum of its proper divisors (257046959).

66061002157 is a wasteful number, since it uses less digits than its factorization.

66061002157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 257046958.

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 66061002157 in words is "sixty-six billion, sixty-one million, two thousand, one hundred fifty-seven".