1620552481 has 4 divisors (see below), whose sum is σ = 1658239792. Its totient is φ = 1582865172.

The previous prime is 1620552467. The next prime is 1620552487. The reversal of 1620552481 is 1842550261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1620552481 - 2⁵ = 1620552449 is a prime.

It is a super-2 number, since 2×1620552481² = 5252380687350510722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1620552487) 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, 18843591 + ... + 18843676.

It is an arithmetic number, because the mean of its divisors is an integer number (414559948).

Almost surely, 2^1620552481 is an apocalyptic number.

It is an amenable number.

1620552481 is a deficient number, since it is larger than the sum of its proper divisors (37687311).

1620552481 is an equidigital number, since it uses as much as digits as its factorization.

1620552481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37687310.

The product of its (nonzero) digits is 19200, while the sum is 34.

The square root of 1620552481 is about 40256.0862603408. The cubic root of 1620552481 is about 1174.5937889038.

It can be divided in two parts, 16205 and 52481, that added together give a palindrome (68686).

The spelling of 1620552481 in words is "one billion, six hundred twenty million, five hundred fifty-two thousand, four hundred eighty-one".