172742621 has 2 divisors, whose sum is σ = 172742622. Its totient is φ = 172742620.

The previous prime is 172742617. The next prime is 172742659. The reversal of 172742621 is 126247271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171976996 + 765625 = 13114^2 + 875^2 .

It is a cyclic number.

It is not a de Polignac number, because 172742621 - 2² = 172742617 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (172745621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86371310 + 86371311.

It is an arithmetic number, because the mean of its divisors is an integer number (86371311).

Almost surely, 2^172742621 is an apocalyptic number.

It is an amenable number.

172742621 is a deficient number, since it is larger than the sum of its proper divisors (1).

172742621 is an equidigital number, since it uses as much as digits as its factorization.

172742621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9408, while the sum is 32.

The square root of 172742621 is about 13143.1587147078. The cubic root of 172742621 is about 556.9290028090.

Adding to 172742621 its reverse (126247271), we get a palindrome (298989892).

The spelling of 172742621 in words is "one hundred seventy-two million, seven hundred forty-two thousand, six hundred twenty-one".