81351469 has 4 divisors (see below), whose sum is σ = 81383296. Its totient is φ = 81319644.

The previous prime is 81351461. The next prime is 81351497. The reversal of 81351469 is 96415318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 96415318 = 2 ⋅48207659.

It is a cyclic number.

It is not a de Polignac number, because 81351469 - 2³ = 81351461 is a prime.

It is a super-2 number, since 2×81351469² = 13236123016915922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81351461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11709 + ... + 17314.

It is an arithmetic number, because the mean of its divisors is an integer number (20345824).

Almost surely, 2^81351469 is an apocalyptic number.

It is an amenable number.

81351469 is a deficient number, since it is larger than the sum of its proper divisors (31827).

81351469 is a wasteful number, since it uses less digits than its factorization.

81351469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31826.

The product of its digits is 25920, while the sum is 37.

The square root of 81351469 is about 9019.5049198944. The cubic root of 81351469 is about 433.2997780066.

It can be divided in two parts, 8135 and 1469, that added together give a square (9604 = 98²).

The spelling of 81351469 in words is "eighty-one million, three hundred fifty-one thousand, four hundred sixty-nine".