81367601 has 4 divisors (see below), whose sum is σ = 92991552. Its totient is φ = 69743652.

The previous prime is 81367597. The next prime is 81367603. The reversal of 81367601 is 10676318.

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.

It is a cyclic number.

It is not a de Polignac number, because 81367601 - 2² = 81367597 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81367603) 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, 5811965 + ... + 5811978.

It is an arithmetic number, because the mean of its divisors is an integer number (23247888).

Almost surely, 2^81367601 is an apocalyptic number.

It is an amenable number.

81367601 is a deficient number, since it is larger than the sum of its proper divisors (11623951).

81367601 is a wasteful number, since it uses less digits than its factorization.

81367601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11623950.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 81367601 is about 9020.3991596825. The cubic root of 81367601 is about 433.3284172355.

The spelling of 81367601 in words is "eighty-one million, three hundred sixty-seven thousand, six hundred one".