66238551 has 12 divisors (see below), whose sum is σ = 99838128. Its totient is φ = 42238944.

The previous prime is 66238507. The next prime is 66238553. The reversal of 66238551 is 15583266.

It is not a de Polignac number, because 66238551 - 2⁷ = 66238423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66238553) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 159790 + ... + 160203.

It is an arithmetic number, because the mean of its divisors is an integer number (8319844).

Almost surely, 2^66238551 is an apocalyptic number.

66238551 is a deficient number, since it is larger than the sum of its proper divisors (33599577).

66238551 is a wasteful number, since it uses less digits than its factorization.

66238551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320022 (or 320019 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 66238551 is about 8138.7069611825. The cubic root of 66238551 is about 404.6103064533.

The spelling of 66238551 in words is "sixty-six million, two hundred thirty-eight thousand, five hundred fifty-one".