66450020421 has 16 divisors (see below), whose sum is σ = 90040930560. Its totient is φ = 43583554560.

The previous prime is 66450020419. The next prime is 66450020423. The reversal of 66450020421 is 12402005466.

It is an interprime number because it is at equal distance from previous prime (66450020419) and next prime (66450020423).

It is not a de Polignac number, because 66450020421 - 2¹ = 66450020419 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66450020423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 432300 + ... + 565493.

It is an arithmetic number, because the mean of its divisors is an integer number (5627558160).

Almost surely, 2^66450020421 is an apocalyptic number.

It is an amenable number.

66450020421 is a deficient number, since it is larger than the sum of its proper divisors (23590910139).

66450020421 is a wasteful number, since it uses less digits than its factorization.

66450020421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998156.

The product of its (nonzero) digits is 11520, while the sum is 30.

Adding to 66450020421 its reverse (12402005466), we get a palindrome (78852025887).

The spelling of 66450020421 in words is "sixty-six billion, four hundred fifty million, twenty thousand, four hundred twenty-one".