81422621 has 16 divisors (see below), whose sum is σ = 95256576. Its totient is φ = 68157936.

The previous prime is 81422609. The next prime is 81422651. The reversal of 81422621 is 12622418.

It is a happy number.

It is not a de Polignac number, because 81422621 - 2⁶ = 81422557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81422651) 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, 58880 + ... + 60246.

It is an arithmetic number, because the mean of its divisors is an integer number (5953536).

Almost surely, 2^81422621 is an apocalyptic number.

It is an amenable number.

81422621 is a deficient number, since it is larger than the sum of its proper divisors (13833955).

81422621 is a wasteful number, since it uses less digits than its factorization.

81422621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1568.

The product of its digits is 1536, while the sum is 26.

The square root of 81422621 is about 9023.4483984783. The cubic root of 81422621 is about 433.4260660842.

The spelling of 81422621 in words is "eighty-one million, four hundred twenty-two thousand, six hundred twenty-one".