869400021 has 16 divisors (see below), whose sum is σ = 1337920128. Its totient is φ = 491880000.

The previous prime is 869400013. The next prime is 869400061. The reversal of 869400021 is 120004968.

It is not a de Polignac number, because 869400021 - 2³ = 869400013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (869400011) 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, 202830 + ... + 207071.

It is an arithmetic number, because the mean of its divisors is an integer number (83620008).

Almost surely, 2^869400021 is an apocalyptic number.

It is an amenable number.

869400021 is a deficient number, since it is larger than the sum of its proper divisors (468520107).

869400021 is a wasteful number, since it uses less digits than its factorization.

869400021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410012.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 869400021 is about 29485.5900568396. The cubic root of 869400021 is about 954.4207706177.

Adding to 869400021 its reverse (120004968), we get a palindrome (989404989).

The spelling of 869400021 in words is "eight hundred sixty-nine million, four hundred thousand, twenty-one".