1620985502501 has 2 divisors, whose sum is σ = 1620985502502. Its totient is φ = 1620985502500.

The previous prime is 1620985502473. The next prime is 1620985502503. The reversal of 1620985502501 is 1052055890261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1192223772100 + 428761730401 = 1091890^2 + 654799^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620985502501 - 2²² = 1620981308197 is a prime.

Together with 1620985502503, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1620985502503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810492751250 + 810492751251.

It is an arithmetic number, because the mean of its divisors is an integer number (810492751251).

Almost surely, 2^{1620985502501} is an apocalyptic number.

It is an amenable number.

1620985502501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620985502501 is an equidigital number, since it uses as much as digits as its factorization.

1620985502501 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216000, while the sum is 44.

The spelling of 1620985502501 in words is "one trillion, six hundred twenty billion, nine hundred eighty-five million, five hundred two thousand, five hundred one".