642342461 has 2 divisors, whose sum is σ = 642342462. Its totient is φ = 642342460.

The previous prime is 642342419. The next prime is 642342473. The reversal of 642342461 is 164243246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 330148900 + 312193561 = 18170^2 + 17669^2 .

It is a cyclic number.

It is not a de Polignac number, because 642342461 - 2¹⁴ = 642326077 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642342061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321171230 + 321171231.

It is an arithmetic number, because the mean of its divisors is an integer number (321171231).

Almost surely, 2^642342461 is an apocalyptic number.

It is an amenable number.

642342461 is a deficient number, since it is larger than the sum of its proper divisors (1).

642342461 is an equidigital number, since it uses as much as digits as its factorization.

642342461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 32.

The square root of 642342461 is about 25344.4759464464. The cubic root of 642342461 is about 862.8239873917.

It can be divided in two parts, 6423 and 42461, that added together give a palindrome (48884).

The spelling of 642342461 in words is "six hundred forty-two million, three hundred forty-two thousand, four hundred sixty-one".