1256651564 has 48 divisors (see below), whose sum is σ = 2659507200. Its totient is φ = 507534336.

The previous prime is 1256651563. The next prime is 1256651573. The reversal of 1256651564 is 4651566521.

It is not an unprimeable number, because it can be changed into a prime (1256651563) 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, 96557 + ... + 108795.

It is an arithmetic number, because the mean of its divisors is an integer number (55406400).

Almost surely, 2^1256651564 is an apocalyptic number.

1256651564 is a gapful number since it is divisible by the number (14) 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 1256651564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1329753600).

1256651564 is an abundant number, since it is smaller than the sum of its proper divisors (1402855636).

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

1256651564 is a wasteful number, since it uses less digits than its factorization.

1256651564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12462 (or 12460 counting only the distinct ones).

The product of its digits is 216000, while the sum is 41.

The square root of 1256651564 is about 35449.2815724099. The cubic root of 1256651564 is about 1079.1246805653.

The spelling of 1256651564 in words is "one billion, two hundred fifty-six million, six hundred fifty-one thousand, five hundred sixty-four".