651778025 has 24 divisors (see below), whose sum is σ = 863944704. Its totient is φ = 486569600.

The previous prime is 651777991. The next prime is 651778027. The reversal of 651778025 is 520877156.

It is not a de Polignac number, because 651778025 - 2¹⁶ = 651712489 is a prime.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (651778027) 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, 9752 + ... + 37398.

It is an arithmetic number, because the mean of its divisors is an integer number (35997696).

Almost surely, 2^651778025 is an apocalyptic number.

It is an amenable number.

651778025 is a deficient number, since it is larger than the sum of its proper divisors (212166679).

651778025 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (651778024) it forms an eRAP, since the sums of their prime factors are consecutive (27720 and 27721).

With its predecessor (651778024) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (27716).

651778025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27721 (or 27716 counting only the distinct ones).

The product of its (nonzero) digits is 117600, while the sum is 41.

The square root of 651778025 is about 25529.9436936316. The cubic root of 651778025 is about 867.0282297276.

The spelling of 651778025 in words is "six hundred fifty-one million, seven hundred seventy-eight thousand, twenty-five".