642610101 has 16 divisors (see below), whose sum is σ = 1012982400. Its totient is φ = 354543168.

The previous prime is 642610091. The next prime is 642610121. The reversal of 642610101 is 101016246.

It is not a de Polignac number, because 642610101 - 2⁵ = 642610069 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642610121) 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 in 15 ways as a sum of consecutive naturals, for example, 526986 + ... + 528203.

It is an arithmetic number, because the mean of its divisors is an integer number (63311400).

Almost surely, 2^642610101 is an apocalyptic number.

It is an amenable number.

642610101 is a deficient number, since it is larger than the sum of its proper divisors (370372299).

642610101 is a wasteful number, since it uses less digits than its factorization.

642610101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1055228.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 642610101 is about 25349.7554426073. The cubic root of 642610101 is about 862.9438062114.

Adding to 642610101 its reverse (101016246), we get a palindrome (743626347).

The spelling of 642610101 in words is "six hundred forty-two million, six hundred ten thousand, one hundred one".