1531214021 has 8 divisors (see below), whose sum is σ = 1622099160. Its totient is φ = 1440419328.

The previous prime is 1531214017. The next prime is 1531214033. The reversal of 1531214021 is 1204121351.

It can be written as a sum of positive squares in 4 ways, for example, as 670084996 + 861129025 = 25886^2 + 29345^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1531214021 - 2² = 1531214017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1531213984 and 1531214002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531214221) 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, 13955 + ... + 57071.

It is an arithmetic number, because the mean of its divisors is an integer number (202762395).

Almost surely, 2^1531214021 is an apocalyptic number.

It is an amenable number.

1531214021 is a deficient number, since it is larger than the sum of its proper divisors (90885139).

1531214021 is a wasteful number, since it uses less digits than its factorization.

1531214021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45223.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 1531214021 is about 39130.7298807472. The cubic root of 1531214021 is about 1152.6000455215.

Adding to 1531214021 its reverse (1204121351), we get a palindrome (2735335372).

The spelling of 1531214021 in words is "one billion, five hundred thirty-one million, two hundred fourteen thousand, twenty-one".