1264427640 has 384 divisors, whose sum is σ = 4916920320. Its totient is φ = 275788800.

The previous prime is 1264427639. The next prime is 1264427651. The reversal of 1264427640 is 467244621.

1264427640 is a `hidden beast` number, since 1 + 2 + 6 + 4 + 4 + 2 + 7 + 640 = 666.

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 = 1264427595 and 1264427604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6619945 + ... + 6620135.

It is an arithmetic number, because the mean of its divisors is an integer number (12804480).

Almost surely, 2^1264427640 is an apocalyptic number.

1264427640 is a gapful number since it is divisible by the number (10) 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 1264427640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2458460160).

1264427640 is an abundant number, since it is smaller than the sum of its proper divisors (3652492680).

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

1264427640 is a wasteful number, since it uses less digits than its factorization.

1264427640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 1264427640 is about 35558.7913180412. The cubic root of 1264427640 is about 1081.3459556438.

The spelling of 1264427640 in words is "one billion, two hundred sixty-four million, four hundred twenty-seven thousand, six hundred forty".