65821025 has 12 divisors (see below), whose sum is σ = 86419692. Its totient is φ = 49559040.

The previous prime is 65820971. The next prime is 65821033. The reversal of 65821025 is 52012856.

It can be written as a sum of positive squares in 6 ways, for example, as 256 + 65820769 = 16^2 + 8113^2 .

It is not a de Polignac number, because 65821025 - 2¹⁶ = 65755489 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77012 + ... + 77861.

It is an arithmetic number, because the mean of its divisors is an integer number (7201641).

Almost surely, 2^65821025 is an apocalyptic number.

It is an amenable number.

65821025 is a deficient number, since it is larger than the sum of its proper divisors (20598667).

65821025 is a wasteful number, since it uses less digits than its factorization.

65821025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154900 (or 154895 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 29.

The square root of 65821025 is about 8113.0157771324. The cubic root of 65821025 is about 403.7583779697.

The spelling of 65821025 in words is "sixty-five million, eight hundred twenty-one thousand, twenty-five".