66156987 has 8 divisors (see below), whose sum is σ = 94994704. Its totient is φ = 40711968.

The previous prime is 66156983. The next prime is 66156989. The reversal of 66156987 is 78965166.

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

It is not a de Polignac number, because 66156987 - 2² = 66156983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66156983) 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, 848128 + ... + 848205.

It is an arithmetic number, because the mean of its divisors is an integer number (11874338).

Almost surely, 2^66156987 is an apocalyptic number.

66156987 is a deficient number, since it is larger than the sum of its proper divisors (28837717).

66156987 is a wasteful number, since it uses less digits than its factorization.

66156987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1696349.

The product of its digits is 544320, while the sum is 48.

The square root of 66156987 is about 8133.6945479899. The cubic root of 66156987 is about 404.4441635776. Note that the first 3 decimals are identical.

The spelling of 66156987 in words is "sixty-six million, one hundred fifty-six thousand, nine hundred eighty-seven".