81261258 has 32 divisors (see below), whose sum is σ = 185322816. Its totient is φ = 23532288.

The previous prime is 81261251. The next prime is 81261281. The reversal of 81261258 is 85216218.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81261251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29316 + ... + 31967.

It is an arithmetic number, because the mean of its divisors is an integer number (5791338).

Almost surely, 2^81261258 is an apocalyptic number.

81261258 is an abundant number, since it is smaller than the sum of its proper divisors (104061558).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81261258 is a wasteful number, since it uses less digits than its factorization.

81261258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61318.

The product of its digits is 7680, while the sum is 33.

The square root of 81261258 is about 9014.5026485103. The cubic root of 81261258 is about 433.1395560950.

The spelling of 81261258 in words is "eighty-one million, two hundred sixty-one thousand, two hundred fifty-eight".