101623721 has 2 divisors, whose sum is σ = 101623722. Its totient is φ = 101623720.

The previous prime is 101623703. The next prime is 101623747. The reversal of 101623721 is 127326101.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59892121 + 41731600 = 7739^2 + 6460^2 .

It is a cyclic number.

It is not a de Polignac number, because 101623721 - 2¹⁸ = 101361577 is a prime.

It is not a weakly prime, because it can be changed into another prime (101623771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50811860 + 50811861.

It is an arithmetic number, because the mean of its divisors is an integer number (50811861).

Almost surely, 2^101623721 is an apocalyptic number.

It is an amenable number.

101623721 is a deficient number, since it is larger than the sum of its proper divisors (1).

101623721 is an equidigital number, since it uses as much as digits as its factorization.

101623721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 101623721 is about 10080.8591399741. The cubic root of 101623721 is about 466.6576226705.

Adding to 101623721 its reverse (127326101), we get a palindrome (228949822).

The spelling of 101623721 in words is "one hundred one million, six hundred twenty-three thousand, seven hundred twenty-one".