91022201021 has 6 divisors (see below), whose sum is σ = 96064982622. Its totient is φ = 86231558520.

The previous prime is 91022201009. The next prime is 91022201033. The reversal of 91022201021 is 12010222019.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (91022201009) and next prime (91022201033).

It can be written as a sum of positive squares in only one way, i.e., 55776268900 + 35245932121 = 236170^2 + 187739^2 .

It is not a de Polignac number, because 91022201021 - 2¹⁴ = 91022184637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91022200984 and 91022201002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91022201041) 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 5 ways as a sum of consecutive naturals, for example, 126069170 + ... + 126069891.

It is an arithmetic number, because the mean of its divisors is an integer number (16010830437).

Almost surely, 2^91022201021 is an apocalyptic number.

It is an amenable number.

91022201021 is a deficient number, since it is larger than the sum of its proper divisors (5042781601).

91022201021 is a wasteful number, since it uses less digits than its factorization.

91022201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252139099 (or 252139080 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The spelling of 91022201021 in words is "ninety-one billion, twenty-two million, two hundred one thousand, twenty-one".