642020351 has 16 divisors (see below), whose sum is σ = 779743296. Its totient is φ = 516036096.

The previous prime is 642020273. The next prime is 642020371. The reversal of 642020351 is 153020246.

It is a cyclic number.

It is not a de Polignac number, because 642020351 - 2¹⁸ = 641758207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642020371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23225 + ... + 42701.

It is an arithmetic number, because the mean of its divisors is an integer number (48733956).

Almost surely, 2^642020351 is an apocalyptic number.

642020351 is a deficient number, since it is larger than the sum of its proper divisors (137722945).

642020351 is a wasteful number, since it uses less digits than its factorization.

642020351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19778.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 642020351 is about 25338.1205104088. The cubic root of 642020351 is about 862.6797389466.

Adding to 642020351 its reverse (153020246), we get a palindrome (795040597).

The spelling of 642020351 in words is "six hundred forty-two million, twenty thousand, three hundred fifty-one".