1520691881 has 2 divisors, whose sum is σ = 1520691882. Its totient is φ = 1520691880.

The previous prime is 1520691869. The next prime is 1520691883. The reversal of 1520691881 is 1881960251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1147854400 + 372837481 = 33880^2 + 19309^2 .

It is a cyclic number.

It is not a de Polignac number, because 1520691881 - 2⁶ = 1520691817 is a prime.

It is a super-2 number, since 2×1520691881² = 4625007593878636322, which contains 22 as substring.

Together with 1520691883, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1520691883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760345940 + 760345941.

It is an arithmetic number, because the mean of its divisors is an integer number (760345941).

Almost surely, 2^1520691881 is an apocalyptic number.

It is an amenable number.

1520691881 is a deficient number, since it is larger than the sum of its proper divisors (1).

1520691881 is an equidigital number, since it uses as much as digits as its factorization.

1520691881 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 41.

The square root of 1520691881 is about 38996.0495563333. The cubic root of 1520691881 is about 1149.9538433901.

The spelling of 1520691881 in words is "one billion, five hundred twenty million, six hundred ninety-one thousand, eight hundred eighty-one".