1521428749 has 2 divisors, whose sum is σ = 1521428750. Its totient is φ = 1521428748.

The previous prime is 1521428747. The next prime is 1521428767. The reversal of 1521428749 is 9478241251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1435273225 + 86155524 = 37885^2 + 9282^2 .

It is a cyclic number.

It is not a de Polignac number, because 1521428749 - 2¹ = 1521428747 is a prime.

Together with 1521428747, 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 (1521428747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760714374 + 760714375.

It is an arithmetic number, because the mean of its divisors is an integer number (760714375).

Almost surely, 2^1521428749 is an apocalyptic number.

It is an amenable number.

1521428749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521428749 is an equidigital number, since it uses as much as digits as its factorization.

1521428749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 43.

The square root of 1521428749 is about 39005.4963947390. The cubic root of 1521428749 is about 1150.1395543307.

The spelling of 1521428749 in words is "one billion, five hundred twenty-one million, four hundred twenty-eight thousand, seven hundred forty-nine".