61864921801509 has 16 divisors (see below), whose sum is σ = 86200702528512. Its totient is φ = 39427025864688.

The previous prime is 61864921801493. The next prime is 61864921801517. The reversal of 61864921801509 is 90510812946816.

It is not a de Polignac number, because 61864921801509 - 2⁴ = 61864921801493 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61864921801909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5101834759 + ... + 5101846884.

It is an arithmetic number, because the mean of its divisors is an integer number (5387543908032).

Almost surely, 2^{61864921801509} is an apocalyptic number.

It is an amenable number.

61864921801509 is a deficient number, since it is larger than the sum of its proper divisors (24335780727003).

61864921801509 is a wasteful number, since it uses less digits than its factorization.

61864921801509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10203681736.

The product of its (nonzero) digits is 7464960, while the sum is 60.

The spelling of 61864921801509 in words is "sixty-one trillion, eight hundred sixty-four billion, nine hundred twenty-one million, eight hundred one thousand, five hundred nine".