121720730 has 16 divisors (see below), whose sum is σ = 219731400. Its totient is φ = 48547392.

The previous prime is 121720727. The next prime is 121720747. The reversal of 121720730 is 37027121.

It can be written as a sum of positive squares in 4 ways, for example, as 117007489 + 4713241 = 10817^2 + 2171^2 .

It is a super-2 number, since 2×121720730² = 29631872223465800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 121720696 and 121720705.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13949 + ... + 20928.

Almost surely, 2^121720730 is an apocalyptic number.

121720730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

121720730 is a deficient number, since it is larger than the sum of its proper divisors (98010670).

121720730 is a wasteful number, since it uses less digits than its factorization.

121720730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35233.

The product of its (nonzero) digits is 588, while the sum is 23.

The square root of 121720730 is about 11032.7118153245. The cubic root of 121720730 is about 495.5888377403.

Adding to 121720730 its reverse (37027121), we get a palindrome (158747851).

The spelling of 121720730 in words is "one hundred twenty-one million, seven hundred twenty thousand, seven hundred thirty".