621216461 has 4 divisors (see below), whose sum is σ = 636368124. Its totient is φ = 606064800.

The previous prime is 621216391. The next prime is 621216467. The reversal of 621216461 is 164612126.

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 343360900 + 277855561 = 18530^2 + 16669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621216461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621216467) 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, 7575770 + ... + 7575851.

It is an arithmetic number, because the mean of its divisors is an integer number (159092031).

Almost surely, 2^621216461 is an apocalyptic number.

It is an amenable number.

621216461 is a deficient number, since it is larger than the sum of its proper divisors (15151663).

621216461 is a wasteful number, since it uses less digits than its factorization.

621216461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15151662.

The product of its digits is 3456, while the sum is 29.

The square root of 621216461 is about 24924.2143507072. The cubic root of 621216461 is about 853.2592106671.

Adding to 621216461 its reverse (164612126), we get a palindrome (785828587).

The spelling of 621216461 in words is "six hundred twenty-one million, two hundred sixteen thousand, four hundred sixty-one".