1251283820 has 24 divisors (see below), whose sum is σ = 2683606464. Its totient is φ = 489863936.

The previous prime is 1251283819. The next prime is 1251283829. The reversal of 1251283820 is 283821521.

It is a happy number.

It is a super-2 number, since 2×1251283820² = 3131422396387584800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1251283829) 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, 664637 + ... + 666516.

It is an arithmetic number, because the mean of its divisors is an integer number (111816936).

Almost surely, 2^1251283820 is an apocalyptic number.

1251283820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1251283820 is an abundant number, since it is smaller than the sum of its proper divisors (1432322644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1251283820 is a wasteful number, since it uses less digits than its factorization.

1251283820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331209 (or 1331207 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 1251283820 is about 35373.4903564802. The cubic root of 1251283820 is about 1077.5860063453.

The spelling of 1251283820 in words is "one billion, two hundred fifty-one million, two hundred eighty-three thousand, eight hundred twenty".