81962261 has 2 divisors, whose sum is σ = 81962262. Its totient is φ = 81962260.

The previous prime is 81962227. The next prime is 81962281. The reversal of 81962261 is 16226918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67749361 + 14212900 = 8231^2 + 3770^2 .

It is a cyclic number.

It is not a de Polignac number, because 81962261 - 2⁶ = 81962197 is a prime.

It is a Chen prime.

It is equal to p_4777334 and since 81962261 and 4777334 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81962281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40981130 + 40981131.

It is an arithmetic number, because the mean of its divisors is an integer number (40981131).

Almost surely, 2^81962261 is an apocalyptic number.

It is an amenable number.

81962261 is a deficient number, since it is larger than the sum of its proper divisors (1).

81962261 is an equidigital number, since it uses as much as digits as its factorization.

81962261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 35.

The square root of 81962261 is about 9053.3011106447. The cubic root of 81962261 is about 434.3814894119.

The spelling of 81962261 in words is "eighty-one million, nine hundred sixty-two thousand, two hundred sixty-one".