1253445021 has 24 divisors (see below), whose sum is σ = 1853504640. Its totient is φ = 815882496.

The previous prime is 1253444981. The next prime is 1253445049. The reversal of 1253445021 is 1205443521.

1253445021 is a `hidden beast` number, since 125 + 34 + 4 + 502 + 1 = 666.

It is not a de Polignac number, because 1253445021 - 2⁶ = 1253444957 is a prime.

It is a super-2 number, since 2×1253445021² = 3142248841339380882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1253444021) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 184045 + ... + 190733.

It is an arithmetic number, because the mean of its divisors is an integer number (77229360).

Almost surely, 2^1253445021 is an apocalyptic number.

It is an amenable number.

1253445021 is a deficient number, since it is larger than the sum of its proper divisors (600059619).

1253445021 is a wasteful number, since it uses less digits than its factorization.

1253445021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7185 (or 7182 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 1253445021 is about 35404.0254914607. The cubic root of 1253445021 is about 1078.2060469784.

Adding to 1253445021 its reverse (1205443521), we get a palindrome (2458888542).

The spelling of 1253445021 in words is "one billion, two hundred fifty-three million, four hundred forty-five thousand, twenty-one".