66650431 has 4 divisors (see below), whose sum is σ = 68451832. Its totient is φ = 64849032.

The previous prime is 66650401. The next prime is 66650443. The reversal of 66650431 is 13405666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13405666 = 2 ⋅6702833.

It is a cyclic number.

It is not a de Polignac number, because 66650431 - 2¹⁹ = 66126143 is a prime.

It is a super-2 number, since 2×66650431² = 8884559904971522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66650393 and 66650402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66650401) 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, 900645 + ... + 900718.

It is an arithmetic number, because the mean of its divisors is an integer number (17112958).

Almost surely, 2^66650431 is an apocalyptic number.

66650431 is a deficient number, since it is larger than the sum of its proper divisors (1801401).

66650431 is a wasteful number, since it uses less digits than its factorization.

66650431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801400.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 66650431 is about 8163.9715212634. The cubic root of 66650431 is about 405.4472141644.

It can be divided in two parts, 66650 and 431, that added together give a square (67081 = 259²).

The spelling of 66650431 in words is "sixty-six million, six hundred fifty thousand, four hundred thirty-one".