72161401 has 4 divisors (see below), whose sum is σ = 77712292. Its totient is φ = 66610512.

The previous prime is 72161387. The next prime is 72161423. The reversal of 72161401 is 10416127.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13868176 + 58293225 = 3724^2 + 7635^2 .

It is a cyclic number.

It is not a de Polignac number, because 72161401 - 2¹³ = 72153209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72161431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2775426 + ... + 2775451.

It is an arithmetic number, because the mean of its divisors is an integer number (19428073).

Almost surely, 2^72161401 is an apocalyptic number.

It is an amenable number.

72161401 is a deficient number, since it is larger than the sum of its proper divisors (5550891).

72161401 is a wasteful number, since it uses less digits than its factorization.

72161401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5550890.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 72161401 is about 8494.7866953797. The cubic root of 72161401 is about 416.3273915145.

Adding to 72161401 its reverse (10416127), we get a palindrome (82577528).

The spelling of 72161401 in words is "seventy-two million, one hundred sixty-one thousand, four hundred one".