1249551864 has 96 divisors (see below), whose sum is σ = 3791726640. Its totient is φ = 368409600.

The previous prime is 1249551841. The next prime is 1249551869. The reversal of 1249551864 is 4681559421.

1249551864 is a `hidden beast` number, since 12 + 4 + 9 + 551 + 86 + 4 = 666.

It is a super-2 number, since 2×1249551864² = 3122759721651748992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1249551869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7984 + ... + 50624.

Almost surely, 2^1249551864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1249551864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1895863320).

1249551864 is an abundant number, since it is smaller than the sum of its proper divisors (2542174776).

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

1249551864 is a wasteful number, since it uses less digits than its factorization.

1249551864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42701 (or 42694 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1249551864 is about 35349.0008911143. Note that the first 3 decimals coincide. The cubic root of 1249551864 is about 1077.0885989966.

The spelling of 1249551864 in words is "one billion, two hundred forty-nine million, five hundred fifty-one thousand, eight hundred sixty-four".