138201961 has 2 divisors, whose sum is σ = 138201962. Its totient is φ = 138201960.

The previous prime is 138201941. The next prime is 138201967. The reversal of 138201961 is 169102831.

138201961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128936025 + 9265936 = 11355^2 + 3044^2 .

It is a cyclic number.

It is not a de Polignac number, because 138201961 - 2¹¹ = 138199913 is a prime.

It is equal to p_7816243 and since 138201961 and 7816243 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (138201967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69100980 + 69100981.

It is an arithmetic number, because the mean of its divisors is an integer number (69100981).

Almost surely, 2^138201961 is an apocalyptic number.

It is an amenable number.

138201961 is a deficient number, since it is larger than the sum of its proper divisors (1).

138201961 is an equidigital number, since it uses as much as digits as its factorization.

138201961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 138201961 is about 11755.9330127387. The cubic root of 138201961 is about 517.0168950178.

The spelling of 138201961 in words is "one hundred thirty-eight million, two hundred one thousand, nine hundred sixty-one".