13539961 has 2 divisors, whose sum is σ = 13539962. Its totient is φ = 13539960.

The previous prime is 13539949. The next prime is 13539971. The reversal of 13539961 is 16993531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13461561 + 78400 = 3669^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 13539961 - 2¹³ = 13531769 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13539961.

It is not a weakly prime, because it can be changed into another prime (13539931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6769980 + 6769981.

It is an arithmetic number, because the mean of its divisors is an integer number (6769981).

Almost surely, 2^13539961 is an apocalyptic number.

It is an amenable number.

13539961 is a deficient number, since it is larger than the sum of its proper divisors (1).

13539961 is an equidigital number, since it uses as much as digits as its factorization.

13539961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21870, while the sum is 37.

The square root of 13539961 is about 3679.6685992084. The cubic root of 13539961 is about 238.3448675962.

It can be divided in two parts, 135399 and 61, that added together give a triangular number (135460 = T₅₂₀).

The spelling of 13539961 in words is "thirteen million, five hundred thirty-nine thousand, nine hundred sixty-one".