1310400021 has 16 divisors (see below), whose sum is σ = 1998979200. Its totient is φ = 747982848.

The previous prime is 1310400011. The next prime is 1310400079. The reversal of 1310400021 is 1200040131.

It is a happy number.

It is not a de Polignac number, because 1310400021 - 2¹⁰ = 1310398997 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 (1310400011) 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, 14076 + ... + 53093.

It is an arithmetic number, because the mean of its divisors is an integer number (124936200).

Almost surely, 2^1310400021 is an apocalyptic number.

It is an amenable number.

1310400021 is a deficient number, since it is larger than the sum of its proper divisors (688579179).

1310400021 is an equidigital number, since it uses as much as digits as its factorization.

1310400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68108.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 1310400021 is about 36199.4477996557. The cubic root of 1310400021 is about 1094.2955432227.

Adding to 1310400021 its reverse (1200040131), we get a palindrome (2510440152).

The spelling of 1310400021 in words is "one billion, three hundred ten million, four hundred thousand, twenty-one".