661012477 has 2 divisors, whose sum is σ = 661012478.
Its totient is φ = 661012476.
The previous prime is 661012463. The next prime is 661012501. The reversal of 661012477 is 774210166.
It is a happy number.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 459202041 + 201810436 = 21429^2 + 14206^2
It is a cyclic number.
It is not a de Polignac number, because 661012477 - 219 = 660488189 is a prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (661012427) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330506238 + 330506239.
It is an arithmetic number, because the mean of its divisors is an integer number (330506239).
Almost surely, 2661012477 is an apocalyptic number.
It is an amenable number.
661012477 is a deficient number, since it is larger than the sum of its proper divisors (1).
661012477 is an equidigital number, since it uses as much as digits as its factorization.
661012477 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 14112, while the sum is 34.
The square root of 661012477 is about 25710.1629127472.
The cubic root of 661012477 is about 871.1037547711.
The spelling of 661012477 in words is "six hundred sixty-one million, twelve thousand, four hundred seventy-seven".