1253584021 has 4 divisors (see below), whose sum is σ = 1254695500. Its totient is φ = 1252472544.

The previous prime is 1253584001. The next prime is 1253584027. The reversal of 1253584021 is 1204853521.

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 633075921 + 620508100 = 25161^2 + 24910^2 .

It is a cyclic number.

It is not a de Polignac number, because 1253584021 - 2¹⁹ = 1253059733 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 (1253584027) 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, 554046 + ... + 556303.

It is an arithmetic number, because the mean of its divisors is an integer number (313673875).

Almost surely, 2^1253584021 is an apocalyptic number.

It is an amenable number.

1253584021 is a deficient number, since it is larger than the sum of its proper divisors (1111479).

1253584021 is a wasteful number, since it uses less digits than its factorization.

1253584021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111478.

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 1253584021 is about 35405.9884906494. The cubic root of 1253584021 is about 1078.2459011665.

The spelling of 1253584021 in words is "one billion, two hundred fifty-three million, five hundred eighty-four thousand, twenty-one".