1272121628 has 24 divisors (see below), whose sum is σ = 2459655072. Its totient is φ = 572616704.

The previous prime is 1272121619. The next prime is 1272121681. The reversal of 1272121628 is 8261212721.

It is a junction number, because it is equal to n+sod(n) for n = 1272121594 and 1272121603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 405125 + ... + 408252.

It is an arithmetic number, because the mean of its divisors is an integer number (102485628).

Almost surely, 2^1272121628 is an apocalyptic number.

It is an amenable number.

1272121628 is a deficient number, since it is larger than the sum of its proper divisors (1187533444).

1272121628 is a wasteful number, since it uses less digits than its factorization.

1272121628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 813421 (or 813419 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 1272121628 is about 35666.8140993838. The cubic root of 1272121628 is about 1083.5348364794.

The spelling of 1272121628 in words is "one billion, two hundred seventy-two million, one hundred twenty-one thousand, six hundred twenty-eight".