65420781 has 24 divisors (see below), whose sum is σ = 95280480. Its totient is φ = 39874464.

The previous prime is 65420737. The next prime is 65420783. The reversal of 65420781 is 18702456.

It is not a de Polignac number, because 65420781 - 2⁹ = 65420269 is a prime.

It is a super-2 number, since 2×65420781² = 8559757173299922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65420783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30366 + ... + 32448.

It is an arithmetic number, because the mean of its divisors is an integer number (3970020).

Almost surely, 2^65420781 is an apocalyptic number.

It is an amenable number.

65420781 is a deficient number, since it is larger than the sum of its proper divisors (29859699).

65420781 is a wasteful number, since it uses less digits than its factorization.

65420781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2153 (or 2134 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 65420781 is about 8088.3113812464. The cubic root of 65420781 is about 402.9383232070.

The spelling of 65420781 in words is "sixty-five million, four hundred twenty thousand, seven hundred eighty-one".