1025806640 has 40 divisors (see below), whose sum is σ = 2398211088. Its totient is φ = 408049920.

The previous prime is 1025806609. The next prime is 1025806657. The reversal of 1025806640 is 466085201.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 1025806597 and 1025806606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20942 + ... + 49901.

Almost surely, 2^1025806640 is an apocalyptic number.

1025806640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1025806640 is an abundant number, since it is smaller than the sum of its proper divisors (1372404448).

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

1025806640 is a wasteful number, since it uses less digits than its factorization.

1025806640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71037 (or 71031 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 1025806640 is about 32028.2163099977. The cubic root of 1025806640 is about 1008.5292582574.

The spelling of 1025806640 in words is "one billion, twenty-five million, eight hundred six thousand, six hundred forty".