61657321 has 8 divisors (see below), whose sum is σ = 67320000. Its totient is φ = 56004240.

The previous prime is 61657307. The next prime is 61657327. The reversal of 61657321 is 12375616.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 61657321 - 2⁵ = 61657289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61657327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21055 + ... + 23803.

It is an arithmetic number, because the mean of its divisors is an integer number (8415000).

Almost surely, 2^61657321 is an apocalyptic number.

It is an amenable number.

61657321 is a deficient number, since it is larger than the sum of its proper divisors (5662679).

61657321 is a wasteful number, since it uses less digits than its factorization.

61657321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4799.

The product of its digits is 7560, while the sum is 31.

The square root of 61657321 is about 7852.2175848610. The cubic root of 61657321 is about 395.0586272003.

The spelling of 61657321 in words is "sixty-one million, six hundred fifty-seven thousand, three hundred twenty-one".