1542253021 has 2 divisors, whose sum is σ = 1542253022. Its totient is φ = 1542253020.

The previous prime is 1542253019. The next prime is 1542253049. The reversal of 1542253021 is 1203522451.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1444836121 + 97416900 = 38011^2 + 9870^2 .

It is a cyclic number.

It is not a de Polignac number, because 1542253021 - 2¹ = 1542253019 is a prime.

Together with 1542253019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1542253001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 771126510 + 771126511.

It is an arithmetic number, because the mean of its divisors is an integer number (771126511).

Almost surely, 2^1542253021 is an apocalyptic number.

It is an amenable number.

1542253021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1542253021 is an equidigital number, since it uses as much as digits as its factorization.

1542253021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 1542253021 is about 39271.5293947155. The cubic root of 1542253021 is about 1155.3632337685.

Adding to 1542253021 its reverse (1203522451), we get a palindrome (2745775472).

The spelling of 1542253021 in words is "one billion, five hundred forty-two million, two hundred fifty-three thousand, twenty-one".