1520121901 has 2 divisors, whose sum is σ = 1520121902. Its totient is φ = 1520121900.

The previous prime is 1520121899. The next prime is 1520121937. The reversal of 1520121901 is 1091210251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1202355625 + 317766276 = 34675^2 + 17826^2 .

It is a cyclic number.

It is not a de Polignac number, because 1520121901 - 2¹ = 1520121899 is a prime.

Together with 1520121899, 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 (1520121401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760060950 + 760060951.

It is an arithmetic number, because the mean of its divisors is an integer number (760060951).

Almost surely, 2^1520121901 is an apocalyptic number.

It is an amenable number.

1520121901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1520121901 is an equidigital number, since it uses as much as digits as its factorization.

1520121901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 22.

The square root of 1520121901 is about 38988.7406952315. The cubic root of 1520121901 is about 1149.8101516473.

The spelling of 1520121901 in words is "one billion, five hundred twenty million, one hundred twenty-one thousand, nine hundred one".