20151656401 has 8 divisors (see below), whose sum is σ = 21369735144. Its totient is φ = 18937209600.

The previous prime is 20151656377. The next prime is 20151656407. The reversal of 20151656401 is 10465615102.

It can be written as a sum of positive squares in 4 ways, for example, as 986022801 + 19165633600 = 31401^2 + 138440^2 .

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 20151656401 - 2¹⁵ = 20151623633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20151656407) 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, 896550 + ... + 918751.

It is an arithmetic number, because the mean of its divisors is an integer number (2671216893).

Almost surely, 2^20151656401 is an apocalyptic number.

It is an amenable number.

20151656401 is a deficient number, since it is larger than the sum of its proper divisors (1218078743).

20151656401 is a wasteful number, since it uses less digits than its factorization.

20151656401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1815971.

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

The spelling of 20151656401 in words is "twenty billion, one hundred fifty-one million, six hundred fifty-six thousand, four hundred one".