10215510401861 has 2 divisors, whose sum is σ = 10215510401862. Its totient is φ = 10215510401860.

The previous prime is 10215510401813. The next prime is 10215510402029. The reversal of 10215510401861 is 16810401551201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8640219330625 + 1575291071236 = 2939425^2 + 1255106^2 .

It is a cyclic number.

It is not a de Polignac number, because 10215510401861 - 2²⁶ = 10215443292997 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10215510421861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5107755200930 + 5107755200931.

It is an arithmetic number, because the mean of its divisors is an integer number (5107755200931).

Almost surely, 2^{10215510401861} is an apocalyptic number.

It is an amenable number.

10215510401861 is a deficient number, since it is larger than the sum of its proper divisors (1).

10215510401861 is an equidigital number, since it uses as much as digits as its factorization.

10215510401861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9600, while the sum is 35.

The spelling of 10215510401861 in words is "ten trillion, two hundred fifteen billion, five hundred ten million, four hundred one thousand, eight hundred sixty-one".