1251958421 has 16 divisors (see below), whose sum is σ = 1543567104. Its totient is φ = 990921984.

The previous prime is 1251958397. The next prime is 1251958423. The reversal of 1251958421 is 1248591521.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1251958421 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 (1251958423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92945 + ... + 105558.

It is an arithmetic number, because the mean of its divisors is an integer number (96472944).

Almost surely, 2^1251958421 is an apocalyptic number.

It is an amenable number.

1251958421 is a deficient number, since it is larger than the sum of its proper divisors (291608683).

1251958421 is a wasteful number, since it uses less digits than its factorization.

1251958421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198580.

The product of its digits is 28800, while the sum is 38.

The square root of 1251958421 is about 35383.0244750219. The cubic root of 1251958421 is about 1077.7796234893.

The spelling of 1251958421 in words is "one billion, two hundred fifty-one million, nine hundred fifty-eight thousand, four hundred twenty-one".