1653640221 has 8 divisors (see below), whose sum is σ = 2214741760. Its totient is φ = 1097482752.

The previous prime is 1653640213. The next prime is 1653640231. The reversal of 1653640221 is 1220463561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1653640221 - 2³ = 1653640213 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 (1653640231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235236 + ... + 1236573.

It is an arithmetic number, because the mean of its divisors is an integer number (276842720).

Almost surely, 2^1653640221 is an apocalyptic number.

It is an amenable number.

1653640221 is a deficient number, since it is larger than the sum of its proper divisors (561101539).

1653640221 is a wasteful number, since it uses less digits than its factorization.

1653640221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2472035.

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 1653640221 is about 40664.9753596384. The cubic root of 1653640221 is about 1182.5341070368.

The spelling of 1653640221 in words is "one billion, six hundred fifty-three million, six hundred forty thousand, two hundred twenty-one".