1620542137 has 2 divisors, whose sum is σ = 1620542138. Its totient is φ = 1620542136.

The previous prime is 1620542123. The next prime is 1620542149. The reversal of 1620542137 is 7312450261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 957531136 + 663011001 = 30944^2 + 25749^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620542137 - 2¹⁹ = 1620017849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1620542099 and 1620542108.

It is not a weakly prime, because it can be changed into another prime (1620542537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810271068 + 810271069.

It is an arithmetic number, because the mean of its divisors is an integer number (810271069).

Almost surely, 2^1620542137 is an apocalyptic number.

It is an amenable number.

1620542137 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620542137 is an equidigital number, since it uses as much as digits as its factorization.

1620542137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 1620542137 is about 40255.9577826686. The cubic root of 1620542137 is about 1174.5912897511.

Adding to 1620542137 its reverse (7312450261), we get a palindrome (8932992398).

The spelling of 1620542137 in words is "one billion, six hundred twenty million, five hundred forty-two thousand, one hundred thirty-seven".