1071657721 has 16 divisors (see below), whose sum is σ = 1105125120. Its totient is φ = 1038772800.

The previous prime is 1071657709. The next prime is 1071657731. The reversal of 1071657721 is 1277561701.

It is a cyclic number.

It is not a de Polignac number, because 1071657721 - 2¹³ = 1071649529 is a prime.

It is a super-2 number, since 2×1071657721² = 2296900541957827682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1071657701) 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, 2872891 + ... + 2873263.

It is an arithmetic number, because the mean of its divisors is an integer number (69070320).

Almost surely, 2^1071657721 is an apocalyptic number.

It is an amenable number.

1071657721 is a deficient number, since it is larger than the sum of its proper divisors (33467399).

1071657721 is a wasteful number, since it uses less digits than its factorization.

1071657721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936.

The product of its (nonzero) digits is 20580, while the sum is 37.

The square root of 1071657721 is about 32736.1836657849. The cubic root of 1071657721 is about 1023.3370523926.

The spelling of 1071657721 in words is "one billion, seventy-one million, six hundred fifty-seven thousand, seven hundred twenty-one".