20151562421 has 4 divisors (see below), whose sum is σ = 20152236000. Its totient is φ = 20150888844.

The previous prime is 20151562397. The next prime is 20151562429. The reversal of 20151562421 is 12426515102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20151562421 - 2¹⁸ = 20151300277 is a prime.

It is a super-3 number, since 3×20151562421³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20151562429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289721 + ... + 352478.

It is an arithmetic number, because the mean of its divisors is an integer number (5038059000).

Almost surely, 2^20151562421 is an apocalyptic number.

It is an amenable number.

20151562421 is a deficient number, since it is larger than the sum of its proper divisors (673579).

20151562421 is an equidigital number, since it uses as much as digits as its factorization.

20151562421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673578.

The product of its (nonzero) digits is 4800, while the sum is 29.

The spelling of 20151562421 in words is "twenty billion, one hundred fifty-one million, five hundred sixty-two thousand, four hundred twenty-one".