1620957101 has 2 divisors, whose sum is σ = 1620957102. Its totient is φ = 1620957100.

The previous prime is 1620957097. The next prime is 1620957133. The reversal of 1620957101 is 1017590261.

It is an a-pointer prime, because the next prime (1620957133) can be obtained adding 1620957101 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1597201225 + 23755876 = 39965^2 + 4874^2 .

It is an emirp because it is prime and its reverse (1017590261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1620957101 - 2² = 1620957097 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1620857101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810478550 + 810478551.

It is an arithmetic number, because the mean of its divisors is an integer number (810478551).

Almost surely, 2^1620957101 is an apocalyptic number.

It is an amenable number.

1620957101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620957101 is an equidigital number, since it uses as much as digits as its factorization.

1620957101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 32.

The square root of 1620957101 is about 40261.1115221624. Note that the first 3 decimals coincide. The cubic root of 1620957101 is about 1174.6915384049.

The spelling of 1620957101 in words is "one billion, six hundred twenty million, nine hundred fifty-seven thousand, one hundred one".