61571438221 has 16 divisors (see below), whose sum is σ = 62242632000. Its totient is φ = 60904368000.

The previous prime is 61571438183. The next prime is 61571438281. The reversal of 61571438221 is 12283417516.

It is a cyclic number.

It is not a de Polignac number, because 61571438221 - 2²¹ = 61569341069 is a prime.

It is a super-3 number, since 3×61571438221³ (a number of 33 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61571438281) 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, 58583146 + ... + 58584196.

It is an arithmetic number, because the mean of its divisors is an integer number (3890164500).

Almost surely, 2^61571438221 is an apocalyptic number.

It is an amenable number.

61571438221 is a deficient number, since it is larger than the sum of its proper divisors (671193779).

61571438221 is a wasteful number, since it uses less digits than its factorization.

61571438221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2460.

The product of its digits is 80640, while the sum is 40.

The spelling of 61571438221 in words is "sixty-one billion, five hundred seventy-one million, four hundred thirty-eight thousand, two hundred twenty-one".