157721101 has 8 divisors (see below), whose sum is σ = 161425440. Its totient is φ = 154051248.

The previous prime is 157721089. The next prime is 157721107. The reversal of 157721101 is 101127751.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157721101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (157721107) 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, 750 + ... + 17776.

It is an arithmetic number, because the mean of its divisors is an integer number (20178180).

Almost surely, 2^157721101 is an apocalyptic number.

It is an amenable number.

157721101 is a deficient number, since it is larger than the sum of its proper divisors (3704339).

157721101 is a wasteful number, since it uses less digits than its factorization.

157721101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17243.

The product of its (nonzero) digits is 490, while the sum is 25.

The square root of 157721101 is about 12558.7061833614. The cubic root of 157721101 is about 540.2937370812.

Adding to 157721101 its reverse (101127751), we get a palindrome (258848852).

The spelling of 157721101 in words is "one hundred fifty-seven million, seven hundred twenty-one thousand, one hundred one".