39920623669 has 2 divisors, whose sum is σ = 39920623670. Its totient is φ = 39920623668.

The previous prime is 39920623667. The next prime is 39920623679. The reversal of 39920623669 is 96632602993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32218455025 + 7702168644 = 179495^2 + 87762^2 .

It is a cyclic number.

It is not a de Polignac number, because 39920623669 - 2¹ = 39920623667 is a prime.

It is a super-2 number, since 2×39920623669² (a number of 22 digits) contains 22 as substring.

Together with 39920623667, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39920623661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19960311834 + 19960311835.

It is an arithmetic number, because the mean of its divisors is an integer number (19960311835).

Almost surely, 2^39920623669 is an apocalyptic number.

It is an amenable number.

39920623669 is a deficient number, since it is larger than the sum of its proper divisors (1).

39920623669 is an equidigital number, since it uses as much as digits as its factorization.

39920623669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5668704, while the sum is 55.

The spelling of 39920623669 in words is "thirty-nine billion, nine hundred twenty million, six hundred twenty-three thousand, six hundred sixty-nine".