621213401 has 2 divisors, whose sum is σ = 621213402. Its totient is φ = 621213400.

The previous prime is 621213391. The next prime is 621213403. The reversal of 621213401 is 104312126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 506295001 + 114918400 = 22501^2 + 10720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621213401 is a prime.

Together with 621213403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (621213403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310606700 + 310606701.

It is an arithmetic number, because the mean of its divisors is an integer number (310606701).

Almost surely, 2^621213401 is an apocalyptic number.

It is an amenable number.

621213401 is a deficient number, since it is larger than the sum of its proper divisors (1).

621213401 is an equidigital number, since it uses as much as digits as its factorization.

621213401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 621213401 is about 24924.1529645443. The cubic root of 621213401 is about 853.2578096646.

Adding to 621213401 its reverse (104312126), we get a palindrome (725525527).

The spelling of 621213401 in words is "six hundred twenty-one million, two hundred thirteen thousand, four hundred one".