1521198901 has 2 divisors, whose sum is σ = 1521198902. Its totient is φ = 1521198900.

The previous prime is 1521198883. The next prime is 1521198971. The reversal of 1521198901 is 1098911251.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1299963025 + 221235876 = 36055^2 + 14874^2 .

It is a cyclic number.

It is not a de Polignac number, because 1521198901 - 2⁹ = 1521198389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1521198971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760599450 + 760599451.

It is an arithmetic number, because the mean of its divisors is an integer number (760599451).

Almost surely, 2^1521198901 is an apocalyptic number.

It is an amenable number.

1521198901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521198901 is an equidigital number, since it uses as much as digits as its factorization.

1521198901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 37.

The square root of 1521198901 is about 39002.5499294597. The cubic root of 1521198901 is about 1150.0816327685.

The spelling of 1521198901 in words is "one billion, five hundred twenty-one million, one hundred ninety-eight thousand, nine hundred one".