126601467721 has 3 divisors (see below), whose sum is σ = 126601823533. Its totient is φ = 126601111910.

The previous prime is 126601467719. The next prime is 126601467761. The reversal of 126601467721 is 127764106621.

The square root of 126601467721 is 355811.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 126601467721 - 2¹ = 126601467719 is a prime.

It is a super-2 number, since 2×126601467721² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (126601467761) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 177906 + ... + 533716.

Almost surely, 2^126601467721 is an apocalyptic number.

126601467721 is the 355811-st square number.

126601467721 is the 177906-th centered octagonal number.

It is an amenable number.

126601467721 is a deficient number, since it is larger than the sum of its proper divisors (355812).

126601467721 is an frugal number, since it uses more digits than its factorization.

126601467721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 711622 (or 355811 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 43.

The spelling of 126601467721 in words is "one hundred twenty-six billion, six hundred one million, four hundred sixty-seven thousand, seven hundred twenty-one".