621749 has 2 divisors, whose sum is σ = 621750. Its totient is φ = 621748.

The previous prime is 621739. The next prime is 621757. The reversal of 621749 is 947126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 504100 + 117649 = 710^2 + 343^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (621739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310874 + 310875.

It is an arithmetic number, because the mean of its divisors is an integer number (310875).

2⁶²¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

621749 is a deficient number, since it is larger than the sum of its proper divisors (1).

621749 is an equidigital number, since it uses as much as digits as its factorization.

621749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 29.

The square root of 621749 is about 788.5106213616. The cubic root of 621749 is about 85.3502960393.

The spelling of 621749 in words is "six hundred twenty-one thousand, seven hundred forty-nine".