156651421 has 8 divisors (see below), whose sum is σ = 158553560. Its totient is φ = 154757952.

The previous prime is 156651403. The next prime is 156651433. The reversal of 156651421 is 124156651.

It can be written as a sum of positive squares in 4 ways, for example, as 89984196 + 66667225 = 9486^2 + 8165^2 .

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 156651421 - 2²¹ = 154554269 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 (156651221) 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, 38731 + ... + 42583.

It is an arithmetic number, because the mean of its divisors is an integer number (19819195).

Almost surely, 2^156651421 is an apocalyptic number.

It is an amenable number.

156651421 is a deficient number, since it is larger than the sum of its proper divisors (1902139).

156651421 is a wasteful number, since it uses less digits than its factorization.

156651421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4335.

The product of its digits is 7200, while the sum is 31.

The square root of 156651421 is about 12516.0465403417. The cubic root of 156651421 is about 539.0695235845.

The spelling of 156651421 in words is "one hundred fifty-six million, six hundred fifty-one thousand, four hundred twenty-one".