642506149 has 2 divisors, whose sum is σ = 642506150. Its totient is φ = 642506148.

The previous prime is 642506113. The next prime is 642506167. The reversal of 642506149 is 941605246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 531625249 + 110880900 = 23057^2 + 10530^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642506149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642506549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321253074 + 321253075.

It is an arithmetic number, because the mean of its divisors is an integer number (321253075).

Almost surely, 2^642506149 is an apocalyptic number.

It is an amenable number.

642506149 is a deficient number, since it is larger than the sum of its proper divisors (1).

642506149 is an equidigital number, since it uses as much as digits as its factorization.

642506149 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 642506149 is about 25347.7050045956. The cubic root of 642506149 is about 862.8972722546.

The spelling of 642506149 in words is "six hundred forty-two million, five hundred six thousand, one hundred forty-nine".