1375121421 has 8 divisors (see below), whose sum is σ = 2037216960. Its totient is φ = 916747596.

The previous prime is 1375121399. The next prime is 1375121443. The reversal of 1375121421 is 1241215731.

1375121421 is a `hidden beast` number, since 1 + 3 + 7 + 512 + 142 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (1375121399) and next prime (1375121443).

It is not a de Polignac number, because 1375121421 - 2⁵ = 1375121389 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 50930423 = 1375121421 / (1 + 3 + 7 + 5 + 1 + 2 + 1 + 4 + 2 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1375121821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25465185 + ... + 25465238.

It is an arithmetic number, because the mean of its divisors is an integer number (254652120).

Almost surely, 2^1375121421 is an apocalyptic number.

It is an amenable number.

1375121421 is a deficient number, since it is larger than the sum of its proper divisors (662095539).

1375121421 is an equidigital number, since it uses as much as digits as its factorization.

1375121421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50930432 (or 50930426 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 1375121421 is about 37082.6296397653. The cubic root of 1375121421 is about 1112.0227761863.

The spelling of 1375121421 in words is "one billion, three hundred seventy-five million, one hundred twenty-one thousand, four hundred twenty-one".