1251690228 has 72 divisors (see below), whose sum is σ = 3281241600. Its totient is φ = 401841216.

The previous prime is 1251690157. The next prime is 1251690233. The reversal of 1251690228 is 8220961521.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1251690192 and 1251690201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 498825 + ... + 501327.

It is an arithmetic number, because the mean of its divisors is an integer number (45572800).

Almost surely, 2^1251690228 is an apocalyptic number.

1251690228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1251690228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1640620800).

1251690228 is an abundant number, since it is smaller than the sum of its proper divisors (2029551372).

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

1251690228 is a wasteful number, since it uses less digits than its factorization.

1251690228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3021 (or 3016 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 1251690228 is about 35379.2344179464. The cubic root of 1251690228 is about 1077.7026577828.

The spelling of 1251690228 in words is "one billion, two hundred fifty-one million, six hundred ninety thousand, two hundred twenty-eight".