1025399664 has 60 divisors (see below), whose sum is σ = 2890396600. Its totient is φ = 339334272.

The previous prime is 1025399663. The next prime is 1025399677. The reversal of 1025399664 is 4669935201.

1025399664 is a `hidden beast` number, since 102 + 539 + 9 + 6 + 6 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1025399663) 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 11 ways as a sum of consecutive naturals, for example, 5599 + ... + 45630.

Almost surely, 2^1025399664 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 1025399664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1445198300).

1025399664 is an abundant number, since it is smaller than the sum of its proper divisors (1864996936).

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

1025399664 is a wasteful number, since it uses less digits than its factorization.

1025399664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51382 (or 51373 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 1025399664 is about 32021.8622818849. The cubic root of 1025399664 is about 1008.3958668107.

It can be divided in two parts, 1025 and 399664, that added together give a square (400689 = 633²).

The spelling of 1025399664 in words is "one billion, twenty-five million, three hundred ninety-nine thousand, six hundred sixty-four".