81651410 has 16 divisors (see below), whose sum is σ = 150391296. Its totient is φ = 31900848.

The previous prime is 81651407. The next prime is 81651413. The reversal of 81651410 is 1415618.

81651410 = 2603² + 2604² + ... + 2614².

It is an interprime number because it is at equal distance from previous prime (81651407) and next prime (81651413).

It is a self number, because there is not a number n which added to its sum of digits gives 81651410.

It is not an unprimeable number, because it can be changed into a prime (81651413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94514 + ... + 95373.

It is an arithmetic number, because the mean of its divisors is an integer number (9399456).

Almost surely, 2^81651410 is an apocalyptic number.

81651410 is a deficient number, since it is larger than the sum of its proper divisors (68739886).

81651410 is a wasteful number, since it uses less digits than its factorization.

81651410 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 189937.

The product of its (nonzero) digits is 960, while the sum is 26.

The square root of 81651410 is about 9036.1169757811. The cubic root of 81651410 is about 433.8316469921.

The spelling of 81651410 in words is "eighty-one million, six hundred fifty-one thousand, four hundred ten".