101921201001 has 9 divisors (see below), whose sum is σ = 147220895991. Its totient is φ = 67946828832.

The previous prime is 101921200999. The next prime is 101921201069. The reversal of 101921201001 is 100102129101.

It is a happy number.

The square root of 101921201001 is 319251.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 78335613225 + 23585587776 = 279885^2 + 153576^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 101921201001 - 2¹ = 101921200999 is a prime.

It is not an unprimeable number, because it can be changed into a prime (101921241001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 904545 + ... + 1010961.

Almost surely, 2^101921201001 is an apocalyptic number.

101921201001 is the 319251-st square number.

101921201001 is the 159626-th centered octagonal number.

It is an amenable number.

101921201001 is a deficient number, since it is larger than the sum of its proper divisors (45299694990).

101921201001 is an frugal number, since it uses more digits than its factorization.

101921201001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212840 (or 106420 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

Multiplying 101921201001 by its product of nonzero digits (36), we get a square (3669163236036 = 1915506²).

The spelling of 101921201001 in words is "one hundred one billion, nine hundred twenty-one million, two hundred one thousand, one".