1521469981 has 2 divisors, whose sum is σ = 1521469982. Its totient is φ = 1521469980.

The previous prime is 1521469979. The next prime is 1521470021. The reversal of 1521469981 is 1899641251.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1040062500 + 481407481 = 32250^2 + 21941^2 .

It is a cyclic number.

It is not a de Polignac number, because 1521469981 - 2¹ = 1521469979 is a prime.

It is a super-2 number, since 2×1521469981² = 4629741806168280722, which contains 22 as substring.

Together with 1521469979, 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 (1521469931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760734990 + 760734991.

It is an arithmetic number, because the mean of its divisors is an integer number (760734991).

Almost surely, 2^1521469981 is an apocalyptic number.

It is an amenable number.

1521469981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521469981 is an equidigital number, since it uses as much as digits as its factorization.

1521469981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 46.

The square root of 1521469981 is about 39006.0249320538. The cubic root of 1521469981 is about 1150.1499441536.

The spelling of 1521469981 in words is "one billion, five hundred twenty-one million, four hundred sixty-nine thousand, nine hundred eighty-one".