101021861 has 2 divisors, whose sum is σ = 101021862. Its totient is φ = 101021860.

The previous prime is 101021849. The next prime is 101021923. The reversal of 101021861 is 168120101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59985025 + 41036836 = 7745^2 + 6406^2 .

It is a cyclic number.

It is not a de Polignac number, because 101021861 - 2²⁶ = 33912997 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (101021801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50510930 + 50510931.

It is an arithmetic number, because the mean of its divisors is an integer number (50510931).

Almost surely, 2^101021861 is an apocalyptic number.

It is an amenable number.

101021861 is a deficient number, since it is larger than the sum of its proper divisors (1).

101021861 is an equidigital number, since it uses as much as digits as its factorization.

101021861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 20.

The square root of 101021861 is about 10050.9631876751. The cubic root of 101021861 is about 465.7345479885.

Adding to 101021861 its reverse (168120101), we get a palindrome (269141962).

The spelling of 101021861 in words is "one hundred one million, twenty-one thousand, eight hundred sixty-one".