39920537951381 has 2 divisors, whose sum is σ = 39920537951382. Its totient is φ = 39920537951380.

The previous prime is 39920537951269. The next prime is 39920537951387. The reversal of 39920537951381 is 18315973502993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39861860640625 + 58677310756 = 6313625^2 + 242234^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39920537951381 is a prime.

It is a super-2 number, since 2×39920537951381² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39920537951387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19960268975690 + 19960268975691.

It is an arithmetic number, because the mean of its divisors is an integer number (19960268975691).

Almost surely, 2^{39920537951381} is an apocalyptic number.

It is an amenable number.

39920537951381 is a deficient number, since it is larger than the sum of its proper divisors (1).

39920537951381 is an equidigital number, since it uses as much as digits as its factorization.

39920537951381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 55112400, while the sum is 65.

The spelling of 39920537951381 in words is "thirty-nine trillion, nine hundred twenty billion, five hundred thirty-seven million, nine hundred fifty-one thousand, three hundred eighty-one".