15961261 has 2 divisors, whose sum is σ = 15961262. Its totient is φ = 15961260.

The previous prime is 15961243. The next prime is 15961277. The reversal of 15961261 is 16216951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11526025 + 4435236 = 3395^2 + 2106^2 .

It is a cyclic number.

It is not a de Polignac number, because 15961261 - 2⁵ = 15961229 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15961201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7980630 + 7980631.

It is an arithmetic number, because the mean of its divisors is an integer number (7980631).

Almost surely, 2^15961261 is an apocalyptic number.

15961261 is the 2136-th centered heptagonal number.

It is an amenable number.

15961261 is a deficient number, since it is larger than the sum of its proper divisors (1).

15961261 is an equidigital number, since it uses as much as digits as its factorization.

15961261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 31.

The square root of 15961261 is about 3995.1546903718. The cubic root of 15961261 is about 251.7806786215.

The spelling of 15961261 in words is "fifteen million, nine hundred sixty-one thousand, two hundred sixty-one".