621200561 has 16 divisors (see below), whose sum is σ = 652554240. Its totient is φ = 590587200.

The previous prime is 621200549. The next prime is 621200597. The reversal of 621200561 is 165002126.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621200561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621200521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 555575 + ... + 556691.

It is an arithmetic number, because the mean of its divisors is an integer number (40784640).

Almost surely, 2^621200561 is an apocalyptic number.

It is an amenable number.

621200561 is a deficient number, since it is larger than the sum of its proper divisors (31353679).

621200561 is a wasteful number, since it uses less digits than its factorization.

621200561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1424.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 621200561 is about 24923.8953817416. The cubic root of 621200561 is about 853.2519308980.

Adding to 621200561 its reverse (165002126), we get a palindrome (786202687).

It can be divided in two parts, 621200 and 561, that multiplied together give a triangular number (348493200 = T₂₆₄₀₀).

The spelling of 621200561 in words is "six hundred twenty-one million, two hundred thousand, five hundred sixty-one".