66501222031 has 4 divisors (see below), whose sum is σ = 66692868552. Its totient is φ = 66309575512.

The previous prime is 66501221989. The next prime is 66501222097. The reversal of 66501222031 is 13022210566.

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

It is a cyclic number.

It is not a de Polignac number, because 66501222031 - 2¹³ = 66501213839 is a prime.

It is a super-2 number, since 2×66501222031² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66501222131) 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, 95822740 + ... + 95823433.

It is an arithmetic number, because the mean of its divisors is an integer number (16673217138).

Almost surely, 2^66501222031 is an apocalyptic number.

66501222031 is a deficient number, since it is larger than the sum of its proper divisors (191646521).

66501222031 is a wasteful number, since it uses less digits than its factorization.

66501222031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191646520.

The product of its (nonzero) digits is 4320, while the sum is 28.

Adding to 66501222031 its reverse (13022210566), we get a palindrome (79523432597).

The spelling of 66501222031 in words is "sixty-six billion, five hundred one million, two hundred twenty-two thousand, thirty-one".