7721401 has 2 divisors, whose sum is σ = 7721402. Its totient is φ = 7721400.

The previous prime is 7721393. The next prime is 7721423. The reversal of 7721401 is 1041277.

It is an a-pointer prime, because the next prime (7721423) can be obtained adding 7721401 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7645225 + 76176 = 2765^2 + 276^2 .

It is a cyclic number.

It is not a de Polignac number, because 7721401 - 2³ = 7721393 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (7721101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3860700 + 3860701.

It is an arithmetic number, because the mean of its divisors is an integer number (3860701).

Almost surely, 2^7721401 is an apocalyptic number.

It is an amenable number.

7721401 is a deficient number, since it is larger than the sum of its proper divisors (1).

7721401 is an equidigital number, since it uses as much as digits as its factorization.

7721401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 7721401 is about 2778.7409019194. The cubic root of 7721401 is about 197.6508573411.

Adding to 7721401 its reverse (1041277), we get a palindrome (8762678).

The spelling of 7721401 in words is "seven million, seven hundred twenty-one thousand, four hundred one".