1642560221 has 4 divisors (see below), whose sum is σ = 1665694944. Its totient is φ = 1619425500.

The previous prime is 1642560197. The next prime is 1642560223. The reversal of 1642560221 is 1220652461.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1220652461 = 7 ⋅174378923.

It is a cyclic number.

It is not a de Polignac number, because 1642560221 - 2¹⁰ = 1642559197 is a prime.

It is a super-2 number, since 2×1642560221² = 5396008159223137682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642560223) 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, 11567255 + ... + 11567396.

It is an arithmetic number, because the mean of its divisors is an integer number (416423736).

Almost surely, 2^1642560221 is an apocalyptic number.

It is an amenable number.

1642560221 is a deficient number, since it is larger than the sum of its proper divisors (23134723).

1642560221 is an equidigital number, since it uses as much as digits as its factorization.

1642560221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23134722.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 1642560221 is about 40528.5112112449. The cubic root of 1642560221 is about 1179.8870477443.

The spelling of 1642560221 in words is "one billion, six hundred forty-two million, five hundred sixty thousand, two hundred twenty-one".