642703951 has 2 divisors, whose sum is σ = 642703952. Its totient is φ = 642703950.

The previous prime is 642703931. The next prime is 642703961. The reversal of 642703951 is 159307246.

642703951 = T₂₀₆₉₈ + T₂₀₆₉₉ + T₂₀₇₀₀.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642703951 is a prime.

It is equal to p_33433867 and since 642703951 and 33433867 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642703951.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642703931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321351975 + 321351976.

It is an arithmetic number, because the mean of its divisors is an integer number (321351976).

Almost surely, 2^642703951 is an apocalyptic number.

642703951 is the 20700-th centered triangular number.

642703951 is a deficient number, since it is larger than the sum of its proper divisors (1).

642703951 is an equidigital number, since it uses as much as digits as its factorization.

642703951 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 45360, while the sum is 37.

The square root of 642703951 is about 25351.6064776968. The cubic root of 642703951 is about 862.9858137127.

The spelling of 642703951 in words is "six hundred forty-two million, seven hundred three thousand, nine hundred fifty-one".