80400021 has 16 divisors (see below), whose sum is σ = 122238144. Its totient is φ = 46566144.

The previous prime is 80400011. The next prime is 80400029. The reversal of 80400021 is 12000408.

It is not a de Polignac number, because 80400021 - 2¹⁴ = 80383637 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80400029) 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, 59971 + ... + 61296.

It is an arithmetic number, because the mean of its divisors is an integer number (7639884).

Almost surely, 2^80400021 is an apocalyptic number.

It is an amenable number.

80400021 is a deficient number, since it is larger than the sum of its proper divisors (41838123).

80400021 is a wasteful number, since it uses less digits than its factorization.

80400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121300.

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 80400021 is about 8966.6058795957. The cubic root of 80400021 is about 431.6039268860.

Adding to 80400021 its reverse (12000408), we get a palindrome (92400429).

The spelling of 80400021 in words is "eighty million, four hundred thousand, twenty-one".